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Large Degenerated Adrenal Adenomas: Radiologic-Pathologic Correlation
Abstract
To correlate the radiologic and pathologic findings and differential diagnosis of large, degenerated adrenal adenomas.
The authors reviewed the radiologic and pathologic characteristics of 30 large adenomas with cystic regions or areas of heterogeneity that were either intrinsic or demonstrated at contrast material-enhanced computed tomography (CT) or magnetic resonance (MR) imaging. Images of 24 adrenocortical carcinomas were also reviewed to determine whether differentiating characteristics existed.
Most of the adrenocortical adenomas were in asymptomatic women. Ten adenomas contained calcification. Pathologic examination revealed good correlation between heterogeneity and liquefied regions. Histologic examination confirmed regions of adenomatous tissue with areas of hemorrhage, amorphous degenerated material, calcification, and fibrosis. Some tumors contained myelolipomatous foci. Although some clinical and imaging findings differed between the groups, no features could be found that enabled the radiologic differentiation of adenomas from carcinomas.
A subgroup of adrenal adenomas are larger, more heterogeneous, and more frequently calcified than those with the usual imaging findings. Central necrosis, hemorrhage, or both are responsible for many of the imaging features. Differentiation of these lesions from other large adrenal masses, including adrenal carcinoma, cannot be made by means of imaging alone; resection is required for the definitive diagnosis.
... The imaging appearance of acute non-traumatic adrenal hemorrhage has previously been described and the CT appearance of typical adenomas is well described. [7][8][9]. Roughly 70% of adrenal adenomas are lipid rich and can be diagnosed with high specificity by CT as they demonstrate attenuation of < 10 Hounsfield units (HU) on unenhanced CT [10]. The remainder are lipid poor with attenuation > 10 HU, most of which will demonstrate ≥ 60% absolute washout at adrenal protocol CT [11]. ...
... Atypical features of adenomas are reported and include heterogeneous attenuation, calcifications, cystic changes, and myelolipomatous degeneration [3]. In particular, large adenomas are more likely to show atypical features and can mimic adrenocortical carcinoma (ACC) [9,14,15]. To our knowledge, there are no reports on the CT findings of chronically hemorrhagic adenomas with pathologic correlation, and it is possible that some of the atypical features of adenomas could be due to internal hemorrhage. ...
... The most relevant prior study is the radiologic-pathologic correlation of large degenerated adenomas performed by Newhouse et al. [9]. The adenomas were larger than in our study (mean size 11.1 cm). ...
Purpose
To describe the appearance of chronically hemorrhagic adenomas on adrenal protocol CT and correlate imaging with pathologic findings.
Methods
Retrospective case series of adult patients with resected adrenal adenomas showing internal hemorrhage at histology. Seven of nine patients underwent pre-operative adrenal protocol CT and 2/7 underwent unenhanced CT with portal venous phase CT. Two abdominal radiologists in consensus assessed the CT images for the presence of calcifications, macroscopic fat, cystic/necrotic appearance, and the presence, pattern, and percent nodule volume of areas < 10 HU on unenhanced CT. Absolute washout was calculated using a large ROI, and ROIs on the highest and lowest attenuating regions on the portal venous phase.
Results
Mean adenoma length was 4.9 cm. All adenomas had areas measuring < 10 HU on unenhanced CT, ranging from < 20 to > 80% nodule volume. Calcifications were present in 4/9 adenomas and gross fat in 4/9 on CT. Of the seven cases with adrenal protocol CT, the absolute washout was < 60% in 5/7 using the large ROI, 5/7 using the low attenuation ROI, and 7/7 using the high attenuation ROI. At histology, all nine cases had microscopic evidence of hemorrhage, lipid rich adenoma cells, and fibrosclerosis. Myelolipomatous changes were identified in 4/9 cases, with the remaining five cases showing lipomatous metaplasia without a myeloid component.
Conclusion
Chronically hemorrhagic adrenal adenomas demonstrated variable areas < 10 HU on unenhanced CT corresponding to lipid rich adenoma cells. Absolute washout was most often < 60%, hypothesized to be due to fibrosclerosis within the adenomas.
... Imaging appearance of adrenal hemorrhage depends largely on its chronological age or stage of evolution [34]. On non-contrast CT, acute and subacute adrenal hemorrhage appears as parenchymal heterogeneity with foci of increased attenuation and gland enlargement [15,35,36]. MRI is regarded as the most sensitive and specific imaging modality for detection of adrenal hemorrhage [34,37]. ...
... Large adrenal adenomas that undergo degenerative changes including intra-tumoral hemorrhage often subsequently develop areas of cystic and pseudocystic changes and fibrosis [36]. Newhouse et al. studied large degenerated adrenal adenomas with size ranging between 5 and 20 cm and found that cystic changes may range from focal cystic areas to complete cystic appearances [36]. ...
... Large adrenal adenomas that undergo degenerative changes including intra-tumoral hemorrhage often subsequently develop areas of cystic and pseudocystic changes and fibrosis [36]. Newhouse et al. studied large degenerated adrenal adenomas with size ranging between 5 and 20 cm and found that cystic changes may range from focal cystic areas to complete cystic appearances [36]. In another study by Erikson et al., pseudocysts proved to be the most common adrenal cysts representing 78% of their dataset with 19% of those associated with an adrenal neoplasm including adrenal adenoma, adrenocortical carcinoma, and pheochromocytomas [43]. ...
Adrenal adenoma is the most common adrenal lesion. Due to its wide prevalence, adrenal adenomas may demonstrate various imaging features. Thus, it is important to identify typical and atypical imaging features of adrenal adenomas and to be able to differentiate atypical adrenal adenomas from potentially malignant lesions. In this article, we will discuss the diagnostic approach, typical and atypical imaging features of adrenal adenomas, as well as other lesions that mimic adrenal adenomas.
... Our findings suggest that for the evaluation of pheochromocytoma, T2-weighted imaging may be considered specific but with decreased sensitivity. It has been reported [18,34] that in rare instances adrenal adenomas may have very high SI on T2-weighted images owing to internal cystic change and degeneration. However, this typically occurs in adenomas larger than 4 cm [34], which are typically managed surgically [10]. ...
... It has been reported [18,34] that in rare instances adrenal adenomas may have very high SI on T2-weighted images owing to internal cystic change and degeneration. However, this typically occurs in adenomas larger than 4 cm [34], which are typically managed surgically [10]. T2-weighted SI ratio should also be interpreted cautiously in any adrenal nodule larger than 4 cm because necrosis and cystic change in adrenal cortical carcinoma and metastases can elevate T2-weighted SI [7]. ...
... We did not assess lesion heterogeneity subjectively or quantitatively in this study. It had been previously found that large pheochromocytomas are commonly heterogeneous [11]; however, this finding can also be seen in large adenomas [34]. Whether subjective or quantitative analysis of homogeneity can improve accuracy for the diagnosis of the subset of pheochromocytomas that have lower T2-weighted SI may be an area of future study. ...
Objective:
The purpose of this study was to use quantitative analysis to assess MRI and washout CT in the diagnosis of pheochromocytoma versus adenoma.
Materials and methods:
Thirty-four pheochromocytomas (washout CT, 5; MRI, 24; both MRI and CT, 5) resected between 2003 and 2014 were compared with 39 consecutive adenomas (washout CT, 9; MRI, 29; both MRI and CT, 1). A blinded radiologist measured unenhanced attenuation, 70-second peak CT enhancement, 15-minute relative and absolute percentage CT washout, chemical-shift signal intensity index, adrenal-to-spleen signal intensity ratio, T2-weighted signal intensity ratio, and AUC of the contrast-enhanced MRI curve. Comparisons between groups were performed with multivariate and ROC analyses.
Results:
There was no difference in age or sex between the groups (p > 0.05). For CT, pheochromocytomas were larger (4.2 ± 2.5 [SD] vs 2.3 ± 0.9 mm; p = 0.02) and had higher unenhanced attenuation (35.7 ± 6.8 HU [range, 24-48 HU] vs 14.0 ± 20.9 HU [range, -19 to 52 HU]; p = 0.002), greater 70-second peak CT enhancement (92.8 ± 31.1 HU [range, 41.0-143.1 HU] vs 82.6 ± 29.9 HU [range, 50.0-139.0 HU ]; p = 0.01), lower relative washout CT (21.7 ± 24.7 [range, -29.3 to 53.7] vs 65.3 ± 22.3 [range, 32.9-115.3]; p = 0.002), and lower absolute washout CT (31.9 ± 42.8 [range, -70.6 to 70.2] vs 76.9 ± 10.3 [range, 60.3-89.6]; p = 0.001). Thirty percent (3/10) of pheochromocytomas had absolute CT washout in the adenoma range (> 60%). For MRI, pheochromocytomas were larger (5.0 ± 4.2 vs 2.0 ± 0.7 mm; p = 0.003) and had a lower chemical-shift signal intensity index and higher adrenal-to-spleen signal intensity ratio (-3.5% ± 14.3% [range, -56.3% to 12.2%] and 1.1% ± 0.1% [range, 0.9-1.3%] vs 47.3% ± 27.8% [range, -9.4% to 86.0%] and 0.51% ± 0.27% [range, 0.13-1.1%]) (p < 0.001) and higher T2-weighted signal intensity ratio (4.4 ± 2.4 vs 1.8 ± 0.8; p < 0.001). There was no statistically significant difference in contrast-enhanced MRI AUC (288.9 ± 265.3 vs 276.2 ± 129.9 seconds; p = 0.96). The ROC AUC for T2-weighted signal intensity ratio was 0.91 with values greater than 3.8 diagnostic of pheochromocytoma.
Conclusion:
In this study, the presence of intracellular lipid on unenhanced CT or chemical-shift MR images was diagnostic of adrenal adenoma. Elevated T2-weighted signal intensity ratio was specific for pheochromocytoma but lacked sensitivity. There was overlap in all other MRI and CT washout parameters.
... According to the functional capacity, adenomas can either be classified as non-hyperfunctioning (normal hormone levels), representing 85% of all adenomas or hyperfunctioning, which accounts for 15% (primary hyperaldosteronism, Cushing syndrome, and hyperandrogenism). Adrenal adenomas are typically ovoid in shape, well-defined, and often homogeneous in attenuation (87% homogeneous on pre-contrast images, 58% homogeneous on postcontrast images) [7][8][9][10] . Adenomas typically range from 2-3 cm 11,12 . ...
... Adenomas typically range from 2-3 cm 11,12 . Large adenomas may have calcification, heterogeneity, or necrosis, but those characteristics are considered atypical features 10 . Most adrenal lesions which measure less 4 cm are considered benign. ...
Imaging plays an essential role in approaching adrenal diseases. The prevalence of adrenal incidentalomas ranges from 3 to 7% of all cross-sectional abdominal exams in adults, requiring specific knowledge and expertise of radiologists to adequately deal with this situation. On the other side, despite the diagnosis of clinical adrenal-related syndromes relying on clinical and laboratory criteria, imaging is still essential to define the etiology of these conditions and/or to indicate the best therapeutical management. This article focuses on essential knowledge of anatomy and to review the common computed tomography (CT) and magnetic resonance imaging (MRI) characteristics of the most common abnormalities of adrenal glands where imaging plays a role.
... Their presentation on CT, let alone on MRI, has been poorly studied. The imaging features of 24 large heterogeneous degenerated adrenal adenomas as well as their differentiation from adrenocortical carcinomas (ACC) have been reported in the late 1990s, but no evaluation of the presence of microscopic or macroscopic fat on CT/MRI was performed [10]. Since then, Gabriel et al. suggested that an adrenal lesion with heterogeneous signal drop on CSI, thus in part containing microscopic fat, was highly likely to be a benign adrenal lesion [11]. ...
... Lastly, our findings of a high proportion of calcifications in heterogeneous adenomas (45.8%) are consistent with two other studies reporting a frequency of 40% of calcifications in large adenomas [10,12]. We assume that calcifications represent the eventual evolution of underlying Fig. 3 Incidentally discovered right, 5-cm-large adrenal mass in a 62-year-old man on computed tomography (CT). ...
PurposeTo assess whether heterogeneous adrenal adenomas can be distinguished from heterogeneous non-adenomas with Computed Tomography (CT) and/or Magnetic Resonance Imaging (MRI).Method
From 2009 to 2019, 980 consecutive adrenalectomies were retrospectively identified. Patients without adequate CT/MRI, with homogeneous and/or < 1 cm lesions were excluded. Differences between adenomas and non-adenomas were analyzed using Chi-square, Student t or Fischer tests, and interobserver agreement using weighted kappa test or intraclass correlation coefficient. Independent variables associated with adenomas were searched for using multivariable analysis. Area under the receiver operating characteristic curve (AUC) of the final model and its diagnostic performances were calculated.ResultsFinal population comprised 183 patients (106 women, 77 men, mean age 53.2 ± 14.4 years) with 124 non-adenomas and 59 heterogeneous adenomas. Macroscopic or microscopic fat on CT/MRI allowed diagnosis of adenoma with 98% specificity and 63% sensitivity. Interobserver agreement was almost perfect for macroscopic fat (k = 0.82; 95% CI 0.66; 0.94) and substantial for microscopic fat (k = 0.75; 95% CI 0.62; 0.86). A multivariable model including micro- or macroscopic fat [Odds ratio (OR) 81.19; 95% CI 20.17; 572.27], diameter < 5.5 cm (OR 7.32; 95% CI 2.17; 31.28), calcifications (OR 5.68; 95% CI 2.08; 16.18), and hemorrhage (OR 3.10; 95% CI 0.70; 15.35) had an AUC of 0.91 (95% CI 0.86; 0.96), 71% (42/59, 95% CI 58; 82) sensitivity, 93% (115/124; 95% CI 87; 97) specificity, and 86% (157/183; 95% CI 79; 90) accuracy for the diagnosis of adenoma.ConclusionA multivariable model enables CT/MR diagnosis of heterogeneous adenomas. Presence of microscopic fat, even if partial, in a heterogeneous mass is highly specific of adenoma.Graphical abstract
... This confirms what prior investigators have shownnamely, that adenomas tend to appear homogeneous at CT [15,16,37]. Nevertheless, adenomas can appear heterogeneous on CT (particularly at larger sizes) [38], and overall accuracy for the diagnosis of metastases in our study on the basis of subjective evaluation of texture was only modest. In our study, metastases were larger than adenomas; however, there was overlap between groups. ...
... In our study, metastases were larger than adenomas; however, there was overlap between groups. The risk of malignancy increases with adrenal mass size [25,39]; however, adenomas may also be atypically large [38,40]. There was no difference in attenuation of adrenal adenomas or metastases measured at portal venous phase contrast-enhanced CT in our study. ...
... Adrenocortical carcinomas are often demonstrated as large masses, invasion of adjacent structures, quite heterogeneous in appearance, with areas of necrosis, hemorrhage, irregular dystro-phic calcification, and heterogeneous enhancement. [18,19] However, calcifications of angiosarcoma have a more regular shape representing calcified vascular thrombi. [12] In addition, some of the adrenocortical carcinomas may have typical clinical presentation of Cushing syndrome, feminization, virilization, or mixed Cushing syndrome-virilization. ...
... They rarely undergo intratumoral hemorrhage, with subsequent formation of cystic areas and fibrosis. [18,19] Pheochromocytomas often present with larger size, cystic regions, and occasional calcifications, which may simulate angiosarcoma. However, most pheochromocytomas produce endocrine abnormalities and characteristic symptoms that permit a specific diagnosis. ...
Rationale
Angiosarcoma is an extremely rare malignant tumor of endothelial origin. The majority of studies reporting angiosarcoma have been concerned with the clinical and pathological aspects, with limited reporting of their imaging findings. To our knowledge, angiosarcoma of the adrenal gland is very rare. Herein we firstly report a primary adrenal angiosarcoma depicted on magnetic resonance imaging (MRI).
Patient concerns
A 59-year-old man was referred to our hospital for 1 year left-flank pain that exacerbated in recent 4 months.
Diagnosis
A regular mass with clear boundary was revealed on MRI in the region of left adrenal gland. Its signal intensity was inhomogeneous. It mainly showed isointensity with patchy slight hyperintensity on T1-weighted images and marked hyperintensity with patchy hypointensity on T2-weighted images. On contrast-enhanced images, it demonstrated significantly heterogeneous enhancement, and the peripheral solid component showed delayed enhancement. Bulky blood vessels and hemorrhage were identified in the tumor.
Interventions
The mass was surgically excised under a left laparoscopic adrenalectomy.
Outcomes
Left adrenal angiosarcoma was confirmed by pathological and immunohistochemical examinations. No evidence of recurrence was found 6 months after operation.
Lessons
In conclusion, primary adrenal angiosarcoma has some MRI features corresponding to its pathological nature. It should be included in the differential diagnosis when a mass was detected in the adrenal gland.
... Besides, on T2 weighted MRI sequences, adenomas are usually seen as homogenous and exhibit low to intermediate signal intensity than liver and muscles unless they undergo cystic degeneration which is responsible for their heterogeneous appearance. [9,10] Dynamic contrast-enhanced MRI studies have also been shown to be useful in the discrimination of benign adenomas from malignant tumors. [11] Diffusion-weighted imaging (DWI) is not beneficial in the discrimination of adenoma from nonadenoma cases because substantial overlapping occurs between apparent diffusion coefficient (ADC) measurements. ...
Objectives
The purpose of our study was to investigate the role of different magnetic resonance imaging (MRI) parameters in the characterization of adrenal masses.
Methods
A total of 150 patients who presented with 186 adrenal tumors were retrospectively evaluated in this study. Final patient cohort consisted of 17 pheochromocytomas, 3 adrenocortical carcinomas, 24 metastases, 31 lipid-poor adenomas and 111 lipid-rich adenomas. We carried out a visual assessment on FSE (Fast spin echo)T2 weighted images and also calculated T2 signal intensity ratio of all adrenal masses and also performed a qualitative assessment on chemical shift imaging (CSI) together with quantitative calculation using Adrenal to spleen signal intensity (si) ratio and Adrenal si index formulas. On dynamic contrast-enhanced sequences, visual assessment based on enhancement patterns on late-arterial phase images was performed and also mean signal intensity measurements were carried out. All examinations were interpreted by two abdominal radiologists in consensus who were blinded to the clinical and pathological findings. Statistical analysis was performed.
Results
On FSE T2 weighted imaging, isointense to liver and slightly hyperintense than liver was found higher in benign cases, however, in malignant cases moderately and strikingly hyperintense than liver was higher than in benign cases (p=0.001, p<0.01). There was a statistically significant difference between the T2 signal intensity ratio values of adrenal tumor groups (p=0.001, p<0.01). In lipid-rich and lipid-poor adenoma groups, T2 signal intensity ratio values was significantly lower than in pheochromocytoma and metastasis cases. In malignant group, T2 signal intensity ratio values were found statistically significantly higher than in the benign group (p=0.001, p<0.01). There was a statistically significant difference between CSI visual assessment of adrenal tumor groups (p=0.001, p<0.01). Although moderate and significant signal intensity loss was usually detected in lipid-rich adenoma group, never detected in other tumor groups. There was also a statistically significant difference between benign and malignant adrenal tumor groups (p=0.001, p<0.01). In the malignant group, Adrenal to spleen si ratio values were found significantly higher whereas, Adrenal si index values were significantly lower compared to benign tumors (p=0.001, p<0.01). Based on malignancy, there was a statistically significant difference between adrenal tumor groups (p=0.001, p<0.01). Although capillary blush and homogenous type enhancement were more common in benign cases than in malignant ones, peripheral-patchy and strikingly capillary blush type enhancement was more frequent in malignant tumors. Based on malignancy, mean arterial signal intensity values of malignant tumors were statistically higher than benign tumors (p=0.001; p<0.01).
Conclusion
Dynamic contrast-enhanced MRI protocol including CSI aids in the characterization of indeterminate adrenal masses. Herein, the combined use of qualitative and quantitative parameters enables more tumors to be recognized that otherwise would be indeterminate.
... In our study, both cystic degeneration and hemorrhage were not likely to occur in ganglioneuromas and adenomas. It has been reported that cystic degeneration and hemorrhage typically occurs in adenomas when the size was larger than 4 cm [30]. ...
Background
The utility of dual-phase enhanced computerized tomography (CT) scan in distinguishing adrenal ganglioneuromas from lipid-poor adenomas has not been reported. We aimed to retrospectively compare dual-phase enhanced CT findings which were helpful in distinguishing adrenal ganglioneuromas from adrenal lipid-poor adenomas.
Methods
We estimated the dual-phase enhanced CT findings of 258 adrenal masses (42 ganglioneuromas, 216 lipid-poor adenomas) in 258 patients from July 2008 to July 2020 with ganglioneuromas and July 2016 to July 2020 with lipid-poor adenomas. The CT features between ganglioneuromas and lipid-poor adenomas were compared using independent two-sample t test, Mann–Whitney test, and ROC analysis.
Results
Significant differences were detected in CT value of unenhanced (CT U ), CT value of arterial phase (CT A ), CT value of venous phase (CT V ), degree of enhancement in arterial phase, degree of enhancement in portal venous phase, age, tumor size [longest dimension, shortest dimension, mean dimension], shape, calcification between the ganglioneuroma and lipid-poor adenoma groups ( P < 0.05). The results of receiver operating characteristics (ROC) analyses showed that areas under ROC curves of CT U , CT A and CT V were 0.713, 0.878, and 0.914, respectively. When the cut-off values were set at 22.5 HU, 51.5 HU, and 53.5 HU for CT U, CT A , and CT V , respectively, the three parameters had a sensitivity of 46.8%, 67.6%, and 88.0% and a specificity of 100%, 100%, and 88.1% in distinguishing ganglioneuromas from lipid-poor adenomas.
Conclusions
Dual-phase enhanced abdominal CT can exhibit some of the primary imaging characteristics of ganglioneuromas and lipid-poor adenomas used to distinguish between these two entities.
... ACCs in adults also can present with minimal or no symptoms of hormonal excess [10], limiting detection and characterization through laboratory tests [11]. While imaging evidence of local invasion and/or metastases aids the diagnosis of stage 3 and 4 ACCs, distinguishing between stage 1 and 2 ACCs and the subset of large heterogeneous, benign adrenal adenomas has been challenging in clinical practice [12]. In fact, in a recent study of 705 adrenal tumors > 4 cm, 31% were benign adenomas and surgical procedures were performed in 55% of thèse even without presence of hormonal excess, consistent with others finding similar results [13]. ...
Purpose
Distinguishing stage 1–2 adrenocortical carcinoma (ACC) and large, lipid poor adrenal adenoma (LPAA) via imaging is challenging due to overlapping imaging characteristics. This study investigated the ability of deep learning to distinguish ACC and LPAA on single time-point CT images.
Methods
Retrospective cohort study from 1994 to 2022. Imaging studies of patients with adrenal masses who had available adequate CT studies and histology as the reference standard by method of adrenal biopsy and/or adrenalectomy were included as well as four patients with LPAA determined by stability or regression on follow-up imaging. Forty-eight (48) subjects with pathology-proven, stage 1–2 ACC and 43 subjects with adrenal adenoma >3 cm in size demonstrating a mean non-contrast CT attenuation > 20 Hounsfield Units centrally were included. We used annotated single time-point contrast-enhanced CT images of these adrenal masses as input to a 3D Densenet121 model for classifying as ACC or LPAA with five-fold cross-validation. For each fold, two checkpoints were reported, highest accuracy with highest sensitivity (accuracy focused) and highest sensitivity with the highest accuracy (sensitivity focused).
Results
We trained a deep learning model (3D Densenet121) to predict ACC versus LPAA. The sensitivity-focused model achieved mean accuracy: 87.2% and mean sensitivity: 100%. The accuracy-focused model achieved mean accuracy: 91% and mean sensitivity: 96%.
Conclusion
Deep learning demonstrates promising results distinguishing between ACC and large LPAA using single time-point CT images. Before being widely adopted in clinical practice, multicentric and external validation are needed.
... However, they demonstrate contrast enhancement and wash-out on dynamic imaging, which clearly differentiate them from adrenal cysts. Adrenal adenomas, especially when they are large, and undergo degeneration, may also appear as cystic masses in certain patients [11,12]. ...
The detection rates of adrenal masses are increasing with the common and widespread use of cross-sectional imaging. Adrenal adenomas, myelolipomas, metastases, pheochromocytomas, and adrenocortical tumors are well-known and relatively common adrenal tumors. However, there are many less-known neoplastic and nonneoplastic adrenal diseases that might affect the adrenal glands in addition to these common lesions. These rare entities include, but are not limited to, hydatid cysts, congenital adrenal hyperplasia, Wolman disease, adrenal tuberculosis, primary adrenal lymphoma. This article aims to present imaging findings of these unusual lesions in accordance with their pathologic characteristics. We think that the simultaneous presentation of the pathological findings with the imaging features may facilitate the learning process and may potentially enhance the recognition of these entities.
... It should be noted that large adrenal adenomas have been reported to show cystic change. Newhouse et al. examined 30 adrenal adenomas and found 2 to be completely cystic, 12 almost entirely cystic and 3 with Contrastenhanced CT image shows a 6.6 cm heterogeneous right adrenal mass (arrow) with multiple areas of cystic change focal cystic regions [28]. The average size of adenomas was 11.1 cm in that study, larger than the 3.2 cm mean size in our study which likely accounts for the discrepancy. ...
PurposeTo determine the accuracy of cystic appearance within adrenal masses on contrast-enhanced CT in distinguishing pheochromocytomas and malignant adrenal tumors from adenomas.Methods
We performed a retrospective review of adult patients with pathologically proven adrenal tumors who underwent contrast-enhanced abdominal CT. There were 92 patients (mean age 64.7 years, 52 men) with 22 pheochromocytomas, 34 malignant masses, and 36 adenomas. Two abdominal radiologists independently reviewed CT images to determine the presence of cystic appearance within the adrenal masses, defined as focal regions of low attenuation within the tumor that subjectively had fluid density.ResultsCystic appearance was present in 12/22 (55%, 95% CI 32–76%) pheochromocytomas (mean size 5.3 cm), 15/34 (44%, 95% CI 27–62%) malignant masses (mean size 5.8 cm), and 2/36 (5.6%, 95% CI 0.7–9%) adenomas (mean size 3.2 cm). Sensitivity and specificity of cystic appearance for distinguishing pheochromocytoma or malignant masses from adenomas were 48.2% (95% CI 34.7–62.0%) and 94.4% (95% CI 81.3–99.3%), respectively. Cystic appearance was a significant predictor of tumor type (p = 0.015) even after controlling for tumor size. Reader agreement for cystic appearance was almost perfect with a kappa of 0.85.Conclusion
Cystic appearance in adrenal tumors on contrast-enhanced CT has high specificity and low sensitivity for distinguishing pheochromocytoma and malignant adrenal masses from adenomas.
... Larger adenomas tend to be more heterogeneous with possible calcifications [92]. Differentiation of large heterogeneous adenomas from carcinomas is often not possible by imaging (Fig. 13), and lesions larger than 4 cm are generally managed as presumed malignant lesions [6,93]. ...
Adrenocortical carcinoma (ACC) is a rare tumor with a poor prognosis. Most tumors are either metastatic or locally invasive at the time of diagnosis. Differentiation between ACC and other adrenal masses depends on clinical, biochemical, and imaging factors. This review will discuss the genetics, pathological, and imaging feature of ACC.
... It was followed up for a year and remained stable; however, follow-up CT, 2 years later, showed interval growth (not shown). The mass was surgically resected and pathological examination revealed an ACC hemorrhage, mimicking malignancy [81]. A diagnosis of ACA could be suspected in the presence of an unremarkable clinical presentation, stability over time, characteristic rapid washout patterns, lack of absolute features of malignancy such as invasion, and minimal FDG uptake on PET/CT. ...
Due to the widespread use of imaging, incidental adrenal masses are commonly encountered. A number of pitfalls can result in misdiagnosis of these lesions, including inappropriate choice of imaging technique, presence of pseudolesions, and overlap of imaging features of different adrenal lesions. This article explores the potential pitfalls in imaging of the adrenal glands, on computed tomography and magnetic resonance imaging, that can lead to misinterpretation. Clues to correct diagnoses are provided to evade potential misinterpretation.
... 30 Macroscopic fat has been described at imaging in other adrenal cortical tumors, including adenomas with myelolipomatous degeneration (uncommon), ACC (rare), and pheochromocytoma (very rare) 31,32 ; however, in these reported cases the fat content represents a small amount of the overall volume of the tumor. 7,28,29,33,34 The proposed biological mechanism for why adrenal masses besides myelolipoma may contain adipocytes is unclear but has been attributed to tumoral degeneration or de-differentiation. 7,34 RENAL MASSES.-Macroscopic ...
This article proposes a consensus nomenclature for fat‐containing renal and adrenal masses at MRI to reduce variability, improve understanding, and enhance communication when describing imaging findings. The MRI appearance of "macroscopic fat" occurs due to a sufficient number of aggregated adipocytes and results in one or more of: 1) intratumoral signal intensity (SI) loss using fat‐suppression techniques, or 2) chemical shift artifact of the second kind causing linear or curvilinear India‐ink (etching) artifact within or at the periphery of a mass at macroscopic fat–water interfaces. "Macroscopic fat" is most commonly observed in adrenal myelolipoma and renal angiomyolipoma (AML) and only rarely encountered in other adrenal cortical tumors and renal cell carcinomas (RCC). Nonlinear noncurvilinear signal intensity loss on opposed‐phase (OP) compared with in‐phase (IP) chemical shift MRI (CSI) may be referred to as "microscopic fat" and is due to: a) an insufficient amount of adipocytes, or b) the presence of fat within tumor cells. Determining whether the signal intensity loss observed on CSI is due to insufficient adipocytes or fat within tumor cells cannot be accomplished using CSI alone; however, it can be inferred when other imaging features strongly suggest a particular diagnosis. Fat‐poor AML are homogeneously hypointense on T2‐weighted (T2W) imaging and avidly enhancing; signal intensity loss at OP CSI is uncommon, but when present is usually focal and is caused by an insufficient number of adipocytes within adjacent voxels. Conversely, clear‐cell RCC are heterogeneously hyperintense on T2W imaging and avidly enhancing, with the signal intensity loss observed on OP CSI being typically diffuse and due to fat within tumor cells. Adrenal adenomas, adrenal cortical carcinoma, and adrenal metastases from fat‐containing primary malignancies also show signal intensity loss on OP CSI due to fat within tumor cells and not from intratumoral adipocytes.
Level of Evidence: 5
Technical Efficacy Stage: 3
J. Magn. Reson. Imaging 2019
... There is no signal loss on T1-out phase images since they do not usually contain intracellular fat (13). However, regardless of the lesion size, degeneration, necrosis, cystic changes and rarely microscopic or macroscopic fat can be seen (14,15,16). In these situations, it may be confused with adrenocortical carcinoma and metastasis. ...
Adrenal collision tumors are rare tumors composed of two different benign or malignant tumors in the adrenal gland. Radiological features are very helpful in the diagnosis, however it is not always possible to make a definite diagnosis with imaging findings alone because the coexisting masses contain different tissue components. In this paper, we report the imaging findings of an adrenal lesion with pseudocyst and myelolipoma mimicking an adrenocortical carcinoma in a 42-year-old female patient. To the best of our knowledge, this is the first reported case of an adrenal lesion containing myelolipoma and hemorrhagic pseudocyst mimicking an adrenal carcinoma in the literature.
... Small neoplasms tend to be solid, whereas large lesions are oft en cystic or hemorrhagic (Melicow 1977). Non-secreting PHEOs tend to be larger than secreting ones (Newhouse et al. 1999). Cystic degeneration may be so marked that only a thin rim of identifi able cells may remain to disclose the true nature of the lesion. ...
We conducted an extensive review of the literature and tried to cite the most recent recommendations concerning the pheochromocytoma (PHEO).
Pub Med and Google Scholar databases were searched systematically for studies concerning pheochromocytomas (intra-adrenal paragangliomas) from 1980 until 2016. Bibliographies were searched to find additional articles.
More than four times elevation of plasma fractionated metanephrines or elevated 24-h urinary fractionated metanephrines are keys to diagnosing pheochromocytoma. If the results are equivocal then we perform the clonidine test. If we have not done it already, we preferably do a CT scan and/or an MRI scan. The patient needs pre-treatment with α1-blockers at least 10–14 days before operation. Alternatives or sometimes adjuncts are Calcium Channels Blockers and/or β-Blockers. Several familial syndromes are associated with PHEO and genetic testing should be considered.
The biggest problem for pheochromocytoma is to suspect it in the first place. Elevated metanephrines establish the diagnosis. With the proper preoperative preparation the risks during operation and the postoperative period are minimal. If there is a risk of the hereditable mutation, it is strongly suggested that all the patients with pheochromocytoma need clinical genetic testing.
... Small neoplasms tend to be solid, whereas large lesions are oft en cystic or hemorrhagic (Melicow 1977). Non-secreting pheochromocytoma tends to be larger than secreting ones (Newhouse et al. 1999). Cystic degeneration may be so marked that only a thin rim of identifi able cells may remain to disclose the true nature of the lesion. ...
The term “adrenal incidentaloma” is a radiological term. Adrenal incidentalomas are adrenal tumors discovered in an imaging study that has been obtained for indications exclusive to adrenal conditions (Udelsman 2001; Linos 2003; Bulow et al. 2006; Anagnostis et al. 2009). This definition excludes patients undergoing imaging testing as part of staging and work-up for cancer (Grumbach et al. 2003; Anagnostis et al. 2009). Papierska et al. (2013) have added the prerequisite that the size of a tumor must be “greater than 1cm in diameter”, in order to be called incidentaloma. Although in the most cases these masses are non-hypersecreting and benign, they still represent an important clinical concern because of the risk of malignancy or hormone hyperfunction (Barzon et al. 2003). Th e adrenal tumors belong to the commonest incidental findings having been discovered (Kanagarajah et al. 2012).
... Patients with adrenal lesions may also present with symptoms due to acute tumor necrosis or degeneration. This is more likely to happen in the setting of a rapidly growing malignancy outgrowing its blood supply, although adrenal adenomas may rarely present with degeneration ( Fig. 15) [28]. Rarely, a patient with adrenocortical carcinoma may present with acute back pain as a result of renal vein thrombosis and/or mass effect on the adjacent kidney ( Fig. 16) [29]. ...
Multiple traumatic and non-traumatic adrenal emergencies are occasionally encountered during the cross-sectional imaging of emergency department patients. Traumatic adrenal hematomas are markers of severe polytrauma, and can be easily overlooked due to multiple concomitant injuries. Patients with non-traumatic adrenal emergencies usually present to an emergency department with a non-specific clinical picture. The detection and management of adrenal emergencies is based on cross-sectional imaging. Adrenal hemorrhage, adrenal infection, or rupture of adrenal neoplasm require immediate detection to avoid dire consequences. More often however, adrenal emergencies are detected incidentally in patients being investigated for non-specific acute abdominal pain. A high index of suspicion is required for the establishment of timely diagnosis and to avert potentially life-threatening complications. We describe cross-sectional imaging findings in patients with traumatic and non-traumatic adrenal hemorrhage, adrenal infarctions, adrenal infections, and complications of adrenal masses.
The productivc character of the scienti fic thought pi nts out a niethodological means that mclude the demand of the students'job about the information and not bis mere reception and reproduetion. It is essential to —¡ve the students the opportunity of discovering the cogniti ve processes used ¡ti the production of the scientitic knowledge. In this work, wc present the result oí the Starting of a workshop dynamic in a basic subject, the students' answers, and the analysis of the suhject. In the Chair of Medical Bacteriology and Vuology of the School of Medical Sciences. the National Lniversity of Córdoba 1700 students attencled classes in 1997. The subject was developecl with the aetivitics that worked the sanie contenis from two different learning conceptions: (1)workshop activity, non obligatory, construct i ve. and (IT) theorico-practical activity. ohl i gatory and traditional .Tvv'o voluntary and anonymous interviews were done about the valuation that the student gaye to these two acti vities and their basis, one in the middle and the other at the end of the course. 90,55% classi fied dic traditional activity as positi ve. and 9,457 as negative. Regarcling the workshop activity, the 60,571 classified it as positive and the 39,5% as negative The same developed content with two activities made possible the analysis of the irnpact that the two di fferent inethodologies produced on the students . The student's ans\ver to the traditional activity was hetter than the workshop activity (p <0.001 ). The differences in (he student's acceptance between the two option revealed the niajor difficulty of an alternativc rnethodological strategy in the current educational niode].
Wc present a casuistic revision of adrenal pathology, which was studicd in our service during the period Janaury 1977-July2000. We revicwed 59.069 hiopsies and 2.674 autopsies and we 84 cases. founded with the following findings:Primary tumors 25%Secundary tumors 51%lnfectious diseases 11%Miscellane.ous 12%Unsuitable for diagnosis 1% Hyperpiasi as, adenomas, pheochromocy-tomas, neuroblastorna, adenocarcinorna are included within primary tumors.The metaslasic tumors corresponded to: lung, pancreas, mammary gland, kidney and carcinomas; endornetrial adenocarcinoma,lymphoma, melanoma, hepatocarcinoma, gastric carcinoma, testicular teratocareinorn a, sk in epydermoid carcinoma, uteruschoriocarcinoma and a primary germinal tumor of the thymus.Within infectious diseases we founded tuberculosis, hystoplasmosis, cryptoeocosis. hydatidosis.Miscellaneous included hematoma, hemorrhage, pseudocyst, Disseniinated Intravascul ar Coagulation (DIC), athrophy, Wegener's granulomatosis, myelolipo[na, hemorrhagic necrosis. There was only one case which was unsuitable for diagnosis due to insuf'ficient material.
BACKGROUND. CT with adrenal-washout protocol (hereafter, adrenal-protocol CT) is commonly performed to distinguish adrenal adenomas from other adrenal tumors. However, the technique's utility among heterogeneous nodules is not well established, and the optimal method for placing ROIs in heterogeneous nodules is not clearly defined. OBJECTIVE. The purpose of our study was to determine the diagnostic performance of adrenal-protocol CT to distinguish adenomas from nonadenomas among heterogeneous adrenal nodules and to compare this performance among different methods for ROI placement. METHODS. This retrospective study included 164 patients (mean age, 59.1 years; 61 men, 103 women) with a total of 164 heterogeneous adrenal nodules evaluated using adrenal-protocol CT at seven institutions. All nodules had an available pathologic reference standard. A single investigator at each institution evaluated the CT images. ROIs were placed on portal venous phase images using four ROI methods: standard ROI, which refers to a single large ROI in the nodule's center; high ROI, a single ROI on the nodule's highest-attenuation area; low ROI, a single ROI the on nodule's lowest-attenuation area; and average ROI, the mean of the three ROIs on the nodule's superior, middle, and inferior thirds using the approach for the standard ROI. ROIs were then placed in identical locations on unenhanced and delayed phase images. Absolute washout was determined for all methods. RESULTS. The nodules comprised 82 adenomas and 82 nonadenomas (36 pheochromocytomas, 20 metastases, 12 adrenocortical carcinomas, and 14 nodules with other pathologies). The mean nodule size was 4.5 ± 2.8 (SD) cm (range, 1.6-23.0 cm). Unenhanced CT attenuation of 10 HU or less exhibited sensitivity and specificity for adenoma of 22.0% and 96.3% for standard-ROI, 11.0% and 98.8% for high-ROI, 58.5% and 84.1% for low-ROI, and 30.5% and 97.6% for average-ROI methods. Adrenal-protocol CT overall (unenhanced attenuation ≤ 10 HU or absolute washout of ≥ 60%) exhibited sensitivity and specificity for adenoma of 57.3% and 84.1% for the standard-ROI method, 63.4% and 51.2% for the high-ROI method, 68.3% and 62.2% for the low-ROI method, and 59.8% and 85.4% for the average-ROI method. CONCLUSION. Adrenal-protocol CT has poor diagnostic performance for distinguishing adenomas from nonadenomas among heterogeneous adrenal nodules regardless of the method used for ROI placement. CLINICAL IMPACT. Adrenal-protocol CT has limited utility in the evaluation of heterogeneous adrenal nodules.
The radiologic diagnosis of adrenal disease can be challenging in settings of atypical presentations, mimics of benign and malignant adrenal masses, and rare adrenal anomalies. Misdiagnosis may lead to suboptimal management and adverse outcomes. Adrenal adenoma is the most common benign adrenal tumor that arises from the cortex, whereas adrenocortical carcinoma (ACC) is a rare malignant tumor of the cortex. Adrenal cyst and myelolipoma are other benign adrenal lesions and are characterized by their fluid and fat content, respectively. Pheochromocytoma is a rare neuroendocrine tumor of the adrenal medulla. Metastases to the adrenal glands are the most common malignant adrenal tumors. While many of these masses have classic imaging appearances, considerable overlap exists between benign and malignant lesions and can pose a diagnostic challenge. Atypical adrenal adenomas include those that are lipid poor; contain macroscopic fat, hemorrhage, and/or iron; are heterogeneous and/or large; and demonstrate growth. Heterogeneous adrenal adenomas may mimic ACC, metastasis, or pheochromocytoma, particularly when they are 4 cm or larger, whereas smaller versions of ACC, metastasis, and pheochromocytoma and those with washout greater than 60% may mimic adenoma. Because of its nonenhanced CT attenuation of less than or equal to 10 HU, a lipid-rich adrenal adenoma may be mimicked by a benign adrenal cyst, or it may be mimicked by a tumor with central cystic and/or necrotic change such as ACC, pheochromocytoma, or metastasis. Rare adrenal tumors such as hemangioma, ganglioneuroma, and oncocytoma also may mimic adrenal adenoma, ACC, metastasis, and pheochromocytoma. The authors describe cases of adrenal neoplasms that they have encountered in clinical practice and presented to adrenal multidisciplinary tumor boards. Key lessons to aid in diagnosis and further guide appropriate management are provided. © RSNA, 2023 Online supplemental material is available for this article. Quiz questions for this article are available through the Online Learning Center.
This chapter describes the imaging features of endocrine diseases obtained by available modalities, discusses the preferred diagnostic approach and their indications, and compares the manifestation of specific lesions in various imaging techniques. Thyroid nodules are common findings among the adult population with an incidence detected on thyroid ultrasound of up to 70%. Although computed tomography (CT) and magnetic resonance imaging (MRI) yield detailed structural information, they have limited utility in the evaluation of thyroid nodules. CT and MRI can be helpful in localization of the parathyroid glands before operation. Parathyroid glands can have diverse shapes, location, size, or number among different individuals. Primary hyperparathyroidism is diagnosed based on biochemical testing. 4D‐CT has higher sensitivity compared to ultrasound and sestamibi scanning and outperforms them in precise localization of the gland in the accurate quadrant. MRI is often the first‐line and most vital imaging modality in pituitary evaluation due to its sophisticated soft tissue depiction.
Adrenal cystic lesions are generally rare and encompass a wide spectrum of benign and malignant entities. Increased utilisation of cross-sectional imaging has led to increased detection of incidentally discovered adrenal lesions. Many of these lesions are cystic or solid with cystic changes, and the majority are benign; however, some may represent malignant lesions and/or even metastases. Therefore, it is vital to characterise these lesions appropriately and follow-up with laboratory tests and imaging if necessary. Key imaging techniques include computed tomography (CT) and magnetic resonance imaging (MRI). Other supplemental imaging tools include metaiodobenzyl-guanidine (MIBG) scintigraphy and 2-[¹⁸F]-fluoro-2-deoxy-d-glucose positron-emission tomography (FDG-PET). Accurate diagnosis of adrenal cystic lesions is crucial in guiding appropriate evaluation and management of these patients. This review highlights the clinical presentations, pathological and imaging features, and management of cystic adrenal lesions.
Background:
The utility of dual-phase enhanced CT scan in distinguishing ganglioneuromas from lipid-poor adenomas has not been reported. We aimed to prospectively compare CT findings helpful in distinguishing adrenal ganglioneuromas from adrenal lipid-poor adenomas.
Methods:
We estimated the CT findings of 258 adrenal masses (42 ganglioneuromas, 216 lipid-poor adenomas) in 258 patients from July 2008 to July 2020 with ganglioneuromas and July 2016 to July 2020 with lipid-poor adenomas. The CT features between ganglioneuromas and lipid-poor adenomas were compared.
Results:
Significant differences were detected in CT value of unenhanced (CTU), CT value of arterial phase (CTA), CT value of venous phase (CTV), degree of enhancement in arterial phase (DEAP), degree of enhancement in portal venous phase (DEPP), age, tumor size [long diameter (LD), short diameter (SD), mean diameter (MD)], shape, calcification between the ganglioneuroma and lipid-poor adenoma groups (P < 0.05).
The results of receiver operating characteristics (ROC) analyses showed that areas under ROC curves (AUC) of CTU, CTA and CTV were 0.713, 0.878, and 0.914, respectively. When the cut-off values were set at 22.5 HU, 51.5 HU, and 53.5 HU for CTU, CTA, and CTV, respectively the three parameters had a sensitivity of 46.8%, 67.6%, and 88.0% and a specificity of 100%, 100%, and 88.1% in distinguishing between ganglioneuromas and lipid-poor adenomas.
Conclusion:
Dual-phase enhanced abdominal CT can exhibit some of the primary imaging characteristics of ganglioneuromas and lipid-poor adenomas used to distinguish between these two entities.
This chapter on pathology of the adrenal glands covers a wide spectrum of topics including embryology and normal gross anatomy; microscopic anatomy; congenital and other abnormalities; nonneoplastic diseases; adrenal neoplasms; peripheral neuroblastic tumors, neuroblastoma, ganglioneuroblastoma, and ganglioneuroma; other adrenal tumors; and tumors metastatic to the adrenal glands.
Objective:
The purpose of this study is to evaluate whether adrenal metastases can be reliably differentiated from adenomas at single-phase contrast-enhanced CT.
Materials and methods:
Sixty-one consecutive patients from a single-institution lung cancer registry (40 metastases and 36 adenomas) who underwent single-phase contrast-enhanced CT at baseline diagnosis were retrospectively studied by two radiologists (blinded to the diagnoses) who independently evaluated four features previously described in adenomas: smooth margin, rim enhancement, central vein sign (preserved adrenal vein), and homogeneity (using a 5-point Likert scale). A third radiologist measured size and attenuation and performed quantitative texture analysis. Comparisons were performed using chi-square, logistic regression, and ROC analysis.
Results:
Metastases were larger than adenomas (mean [± SD] 24 ± 11 mm [range, 11-66 mm] vs 19 ± 5 mm [range, 11-34 mm]; p = 0.012), with overlap between groups. Attenuation of metastases and adenomas did not differ significantly (58.2 ± 21.0 HU [range, 21.0-108.0] vs 55.5 ± 21.5 HU [range, 14.0-105.0]; p = 0.582). Skewness and kurtosis did not differ between groups (p = 0.612 and 0.978, respectively), whereas entropy was higher in metastases (p = 0.013). The AUC for entropy to diagnose metastases was 0.65 (95% CI, 0.52-0.77). Tumor margin, rim enhancement, and the central vein sign did not differ between groups (p > 0.05). Metastases were considered more heterogeneous by both radiologists (p = 0.001 and 0.011, respectively), and agreement was satisfactory (κ = 0.51). Likert scores of 4 or 5 (mostly or completely heterogeneous) yielded sensitivity and specificity for diagnosis of metastases of 32.5% and 97.2%, respectively, for radiologist 1 and 22.5% and 97.2%, respectively, for radiologist 2.
Conclusion:
Adrenal metastases cannot be reliably differentiated from adenomas at single-phase contrast-enhanced CT. Increased tumor size and heterogeneity were specific findings but showed unacceptably low sensitivity.
Purpose of review:
Pheochromocytomas and paragangliomas (PPGLs) are uncommon catecholamine-producing neuroendocrine neoplasms that usually present with secondary hypertension. This review is to update the current knowledge about these neoplasms, the pathophysiology, genetic aspects and diagnostic and therapeutic algorithms based on scientific literature mostly within the past 3 years.
Recent findings:
Eighty to eighty-five percent of PPGLs arise from the adrenal medulla (pheochromocytomas; PCCs) and the remainder from the autonomic neural ganglia (paragangliomas; PGLs). Catecholamine excess causes chronic or paroxysmal hypertension associated with sweating, headaches and palpitations, the presenting features of PPGLs, and increases the cardiovascular morbidity and mortality. Genetic testing should be considered in all cases as mutations are reported in 35-40% of cases; 10-15% of PCCs and 20-50% of PGLs can be malignant. Measurements of plasma-free metanephrines or 24-h urine-fractionated metanephrines help biochemical diagnosis with high sensitivity and specificity. Initial anatomical localization after biochemical confirmation is usually with computed tomography (CT) or magnetic resonance imaging (MRI). 123Iodine metaiodobenzylguanidine (123I-MIBG) scintigraphy, positron emission tomography (PET) or single-photon emission computed tomography (SPECT) is often performed for functional imaging and prognostication prior to curative or palliative surgery. Clinical and biochemical follow-up is recommended at least annually after complete tumour excision. Children, pregnant women and older people have higher morbidity and mortality risk. De-bulking surgery, chemotherapy, radiotherapy, radionuclide agents and ablation procedures are useful in the palliation of incurable disease. PPGLs are unique neuroendocrine tumours that form an important cause for endocrine hypertension. The diagnostic and therapeutic algorithms are updated in this comprehensive article.
Objective:
The objective of this article is to review the current role of CT and MRI for the characterization of adrenal nodules.
Conclusion:
Unenhanced CT and chemical-shift MRI have high specificity for lipid-rich adenomas. Dual-energy CT provides comparable to slightly lower sensitivity for the diagnosis of lipid-rich adenomas but may improve characterization of lipid-poor adenomas. Nonadenomas containing intracellular lipid pose an imaging challenge; however, nonadenomas that contain lipid may be potentially diagnosed using other imaging features. Multiphase adrenal washout CT can be used to differentiate lipid-poor adenomas from metastases but is limited for the diagnosis of hypervascular malignancies and pheochromocytoma.
The adrenal glands are routinely scanned on every computed tomography (CT) scan or magnetic resonance imaging (MRI) of the abdomen and the chest. Incidental adrenal masses are increasingly being detected because of increasing number of imaging studies that are routinely performed; these lesions are encountered in approximately 5 % of imaged patients with no known adrenal disease [1]. Although the adrenal gland is involved by various diseases, almost all adrenal lesions detected are benign in patients without a history of malignancy. Therefore, diagnostic approach to adrenal lesions in these patients should not be as aggressive as those in oncologic patients.
We have noted an increasing number of cases of enlarged adrenal glands where the underlying diagnosis was masked by a diffusely hemorrhagic process. We identified from our database 59 cases (32 consults; 27 routine) of adrenal glands with diffuse (>25%) hemorrhage received between 2000 and 2014. 53 adrenalectomies and 6 biopsies were identified. The diagnoses after central review were: 41 adrenocortical adenomas, 1 nodular adrenocortical hyperplasia with associated myelolipoma, 1 benign adrenocortical cyst and 10 non-neoplastic adrenal glands with hemorrhage. A definitive diagnosis for the 6 biopsies was precluded by the sample size. The adrenocortical adenomas (size 1-13cm; 25-95% hemorrhage) showed clear cell change in the neoplastic area (10-80% of the tumor), 19 showed focal calcification (1 with ossification), 11 showed areas of papillary endothelial hyperplasia, 10 showed scattered lymphoplasmacytic inflammation, 6 showed benign cortical tissue extending beyond the adrenal capsule into soft tissue, 1 showed necrosis in the form of ghost cells, 2 showed lipomatous change and 6 were associated with incidental benign lesions (1cortical cyst, 1 schwannoma and 4 myelolipomas). 24 of the adrenocortical adenomas were consults where the referring pathologist had trouble classifying the lesion. Of the 10 non-neoplastic adrenals (4.5 to 22cm; 40-80% hemorrhage), 2 were consults. In summary, pathologists have difficulties recognizing adrenocortical adenomas in the setting of a massively enlarged and hemorrhagic adrenal gland. Although there is a correlation between adrenocortical malignancy and size, hemorrhage into non-malignant adrenal glands can result in markedly enlarged adrenals.
We encountered a case of degenerated adrenal adenoma, which was difficult to distinguish from adrenal hemangioma by both the radiological and pathological findings. Degenerated adrenal adenoma is usually large and contains abundant portion of necrosis and hemorrhage. These radiologic features are common to degenerated adrenal adenoma and other degenerated adrenal tumors. Therefore, surgical resection is usually required.
Functional adrenal adenomas of more than 4 centimeters in size are rare. We report a case of adrenal adenoma of 12 centimeters in size, presenting with Cushing's syndrome.
Objective:
Cystic lymphangioma is an uncommon lesion in the adrenal gland. Because of the lesion's rarity, few descriptions of it can be found in the radiology literature. We therefore describe a series of these lesions with a focus on CT characteristics with correlation to gross and microscopic pathology features.
Materials and methods:
Retrospective review identified seven patients with definitive pathologic findings of cystic lymphangioma of the adrenal gland and available diagnostic CT examinations. CT examinations were reviewed for key imaging features and correlated to gross and microscopic pathology. Lesions were generally described in corresponding reports as likely representing adenomas or hematomas based on CT findings.
Results:
All cystic lymphangiomas included in this series were well-circumscribed lesions with low-attenuation internal contents and thin walls, without evidence of solid components or nodularity. No measurable contrast enhancement was seen in these lesions. Six of the seven lesions contained calcifications with one of two patterns: either thick, curvilinear, and dystrophic-appearing or thin and scattered. On gross and microscopic pathology, the lesions were composed of dilated cystic spaces containing serous fluid and lined by bland endothelial cells.
Conclusion:
Though rare, an adrenal cystic lymphangioma should be suspected on CT when a unilocular or multilocular, low-attenuation, nonenhancing lesion is present in the region of the adrenal gland, particularly if the lesion contains either of the above-noted calcification patterns. Recognition of these findings may allow more conservative treatment of selected patients harboring these lesions.
We mentioned CT and MR findings of adrenal tumors which consisted of adrenocortical tumors including hyperplasia, pheochromocytoma, and others. It would be necessary to measure the thickness of adrenal gland in the cases of primary aldosteronism whatever the nodule is found or not. In the cases of pheochromocytoma, it is important to suggest the possibility and recommend MIBG scintigraphy to avoid unnecessary biopsy. Adrenal lymphoma is frequently involved in bilateral glands. Internal necrosis could be seen in the case of AIDS lymphoma.
This fourth edition of Abdominal-Pelvic MRI provides the reader with a significant update on earlier works. Modern diagnostic MRI relies on the practitioner’s ability to distinguish between diseases through pattern recognition and experience, and this landmark reference provides the most complete coverage of magnetic resonance imaging of the abdomen and pelvis, with particular emphasis on illustrating benign, malignant and inflammatory lesions • An established best-seller in this field updated with multiple brand new case figures supplying the reader with high quality examples of diagnoses and anatomy. • Includes discussion of new sequences, such as diffusion-weighted imaging and a new chapter on MR/PET. • Describes techniques and tips for controlling motion, including radial acquisition and shorter breath hold acquisition using techniques of multi-gradient parallel imaging in order to achieve high quality images. • Offers practice advice and recommendations for contrast agents taking into account patient safety, efficacy, and cost. • Accompanying digital edition offers rapid search and easy figure download.
To retrospectively evaluate CT sensitivity for characterizing adrenal adenoma according to lesion size.
Between January 2004 and November 2012, 140 patients with 140 histologically proven adenomas underwent preoperative adrenal CT protocols consisting of unenhanced CT, early enhanced CT, and delayed enhanced CT. Adenomas were divided into three size groups: small adenoma (n = 60), ≥1 to <2 cm; medium adenoma (n = 47), ≥2 to <3 cm; and large adenoma (n = 33), ≥3 cm. Adenoma was diagnosed when a lesion met one of the following criteria: (a) unenhanced CT attenuation value ≤10 HU, (b) absolute percentage washout ≥60%, or (c) relative percentage washout ≥40%. The standard reference was pathologic examination of an adrenalectomy specimen. Adenoma size, lesion attenuation value, or percentage washout was correlated with the Spearman's rank correlation. CT sensitivities were compared between size groups of adenomas with the Fisher's exact test.
As adenoma size increased, the lesion attenuation value (ρ = 0.324; P = 0.001) increased on unenhanced CT, and the absolute (ρ = -0.186; P = 0.028) or relative (ρ = -0.374; P < 0.001) percentage washout decreased on early and delayed enhanced CT. CT sensitivities were 100% (60/60) for small adenomas, 97.9% (46/47) for medium adenomas, and 66.7% (22/33) for large adenomas (P < 0.001).
Adrenal CT protocols misdiagnose a substantial number of large adenomas as non-adenomas because CT sensitivity for adenoma markedly decreases, when the lesion size is 3 cm or larger.
Clinical histories and CT findings were reviewed in 38 patients with primary adrenocortical carcinomas. The primary tumors exhibited central areas of low attenuation representing tumor necrosis (n = 26), irregular contrast enhancement (n = 16), detectable calcification (n = 9), and a thin, capsulelike rim surrounding the tumor (n = 7). Tumors metastasized to liver (n = 9), lung (n = 5), and lymph nodes (n = 5). In eight of nine cases of liver metastasis the primary tumor arose in the left adrenal gland. Evidence of endocrinopathy was present in each of nine patients with lesions 6 cm or less in diameter, but in only two of seven adults with lesions exceeding 15 cm in diameter. We conclude that, contrary to established concepts, adrenocortical carcinoma may present as a smooth, homogeneous, functioning mass 6 cm or less in diameter on CT.
A case of Cushing's syndrome, due to an adrenal adenoma, which responded to dexamethasone with a rise in plasma urinary steroids is described. Further unusual features were radiologically visible calcification and a response to ACTH stimulation.
We present 7 patients (5 adult females and 2 neonate males) with adrenal cysts. The cysts included 1 hydtaid, 1 lymphatic and 5 pseudocysts. Three cysts were diagnosed pre-operatively and all were resected surgically. The existence of true epithelial cysts of the adrenal gland is doubted by many authors; the present series includes most types of adrenal cyst.
Three endothelial cysts and five hemorrhagic cysts (pseudocysts) arose in the adrenal glands of seven patients aged 23-73 years. Four patients were male and three were female. Five were symptomatic and gave abdominal pain as their chief complaint. Endothelial cysts were collapsed or filled with serous fluid, multiloculated, had an endothelial lining, and often contained adrenal cortex in their outer walls. The endothelial lining reacted only weakly for Factor VIII-related antigen (FVIII-RAg), but it stained strongly for collagen type IV (C-IV). The lack of hemorrhage and the FVIII-RAg/C-IV staining pattern in endothelial cysts suggest lymphatic differentiation. Hemorrhagic cysts were spherical, firm masses containing clotted blood and hyalinized thrombus with attenuated adrenal cortex in the outer fibrous wall. Islands of intact cortical cells were present deep within the thrombi of four hemorrhagic cysts. Three of five hemorrhagic cysts stained strongly for FVIII-RAg and C-IV in irregular vascular channels of the attenuated cortex and within the cyst contents. These channels suggest that at least some hemorrhagic cysts arise when hemorrhage occurs in a preexisting blood vascular anomaly. Entrapment of cortical islands by extravasated blood in hemorrhagic cysts may be misdiagnosed as necrotic cortical neoplasm. To avoid confusion, one must recognize the normality of the entrapped cortical cells, identify an intrinsic vascular anomaly, and distinguish thrombus from necrotic tumor.
Structural changes were studied in adrenal glands from 78 adrenalectomized hypertensive patients and 220 hypertensive patients examined at autopsy. The findings were compared with those from 220 normotensive autopsied cases. Adrenocortical adenomas were ten times more frequent in hypertensive than in normotensive persons. Only 5 per cent of the adenomas were identified as producing aldosterone. Cell densities of the zona glomerulosa in hypertensive adrenalectomy material were significantly greater than in autopsied normotensive and hypertensive cases, possibly reflecting a relative hypoactivity of the outermost cortical zone. Nodular overgrowths of adrenal cortex were about twice as frequent in hypertensive as in normotensive persons, and dehydrogenase activity of the nodules reflected an abnormality of their metabolism. Adrenal weights, lipoid content, venous wall thickness, and other morphologic aspects investigated were not significantly different in the hypertensive and control series.
Because of their rarity cysts of the adrenal gland are often misinterpreted and misdiagnosed. Six cases of surgically removed adrenal cysts are presented, including 3 endothelial cysts, 2 epithelial retention cysts and 1 pseudocyst. Evidence is presented that epithelial retention cysts could and do develop in the human adrenal cortex and are not theoretically impossible as propagated in the literature. We also emphasize the importance of evaluating the surrounding fibrous and adrenal tissue in the proper identification of these cysts, a point not sufficiently stressed previously.
Only 13 cases of adrenal hemangiomas have been reported, none studied angiographically. Two additional cases, evaluated preoperatively, are presented. The radiographic finding of phleboliths, when present, with the characteristic angiographic appearance of hemangiomas, allows the radiologist to correctly diagnose this benign tumor preoperatively, and where surgical risk is high, prevent a serious operative procedure.
A very rare case of echinococcal cyst of the adrenal gland is reported. Other organs were free of echinococcal cysts. Treatment consisted of surgical removal of the adrenal cyst through a subcostal incision.
The purpose of this report was to suggest the ability to differentiate adrenal masses by out-of-phase FLASH imaging. The images were obtained with breath-holding at TR/TE 100/12 ms, flip angle 20 degrees. The material included adrenal adenoma (n = 16), nodular hyperplasia (n = 1), pheochromocytoma (n = 5), and adrenal metastatic tumors (n = 7). The signal intensity ratios of the adrenal mass/the diaphragmatic crus, back muscle, and renal cortex were obtained. The mean values of the ratios of adenomas or nodular hyperplasia were significantly different from pheochromocytomas or metastases. Although the number of adrenal masses was fairly small, the ratios of adrenal mass/diaphragmatic crus could distinguish them with no overlapping case. All 17 masses with the ratio of 1.16 or less were adenomas or nodular hyperplasia, whereas all 12 masses with a ratio greater than 1.23 were pheochromocytomas or metastases. This result suggests the ability of out-of-phase FLASH imaging to differentiate adrenal masses.
A 42-year-old woman was referred to our hospital for evaluation of severe hypertension. A right adrenal tumor was revealed by CT scan, and the elevation of cortisol and u-17OHCS was found. We made a diagnosis of adrenal adenoma with Cushing's syndrome and performed right adrenalectomy. However, a small myelolipoma (1.5 mm in diameter) was found beside the cortical adenoma by histopathological examination. Adrenal myelolipoma is not a rare disease now, because it is easily-detected as an incidental by CT scan. The present case of adrenal myelolipoma, however, is interesting and uncommon in its connection with functioning cortical adenoma. Only 3 cases have been previously reported so far in English and Japanese publications. We discuss the etiology of adrenal myelolipoma, and suggest that myelolipoma would develop in the course of regressive or necrotic degeneration of cortical cells by hormonal disorders, stress, circulatory disturbance or other unknown factors.
We report the case of a massive hemorrhagic/thrombosed functional adrenal adenoma, a very uncommon mass lesion of the adrenal gland. The lesion contained large areas that histologically mimicked the pattern of an angiosarcoma. Immunoperoxidase staining confirmed that the vascular lining cells were positive for vimentin and negative for three vascular markers (factor VIII antigen, Ulex europaeus agglutinin I, thrombomodulin), cytokeratin, keratin, epithelial membrane antigen, and S100 antigen. Endothelial immunohistochemical markers can be useful as a diagnostic adjunct in differentiating this type of reactive hemorrhagic/thrombotic lesion from angiosarcoma.
To clarify the indication of surgery in incidentally discovered asymptomatic adrenal masses, we analyzed 386 Japanese cases, 379 cases reported in Japan during the past 25 years (from 1964 to 1988) and 7 cases from our own experience. From a total of 460 patients, we carefully selected 379 patients satisfying our criterion of the absence of symptoms and signs suggestive of active hormone over-secretion as described in each case report. From the Japanese series, there was a high incidence of pheochromocytoma patients (20 of 37 patients) who had no symptoms and signs but had high plasma or urine catecholamines. Scintigraphy with 131I-meta-iodo-benzyl-guanidine was useful in the diagnosis of pheochromocytoma. For the other asymptomatic adrenal tumors, except for myelolipoma and adrenal cyst, differential diagnosis between malignant and benign adrenal lesions by imaging procedures such as whole body computed tomography (CT), ultrasonography (US), adrenocortical scintigraphy, and angiography was not always possible. In addition, among the 109 patients with cortical tumors whose hormonal data were reported, no clear-cut differentiation of malignant tumor from benign by means of these data could be obtained. Since 1980 whole body CT scanner and high resolution US scanner have become widely available, and there have been 283 cases of asymptomatic adrenal tumors who satisfied our criterion. Cortical carcinomas smaller than 3 cm and 6 cm in diameter account for 3.8% and 6.6%, respectively, of the total of 101 cases of cortical carcinoma, cortical adenoma, ganglioneuroma, and hemangioma during this period. The size of the smallest cortical carcinoma with metastasis was 2 cm in diameter in this series. Pre-operatively, an adrenocortical carcinoma 2.8 cm in diameter in our patient could not be diagnosed as such by imaging techniques and measurement of plasma hormones. These findings suggest that an adrenal mass larger than 3 cm should be removed and a patient with a smaller cortical tumor should be carefully followed up.
Adrenal cysts are rare, but they have been disproportionately associated with hypertension. This report describes a hypertensive patient with increased levels of 19-nor-deoxycorticosterone (19-nor-DOC), a potent mineralocorticoid. The patient was a thirty year old man with hypokalemia, moderately severe hypertension, suppressed PRA, and low aldosterone secretion. Following surgical removal of a 10 cm adrenal cyst, the hypertension improved, the hypokalemia resolved, and the PRA and the aldosterone secretion normalized. Urinary 19-nor-DOC pre-op was elevated 4.6 microgram per day (normal less than 1.0 microgram/day and subsequently became normal at 0.7 microgram per day following surgery. The adrenal cyst was a fibrous walled structure containing mucinous straw-colored fluid. Pericystic adrenocortical tissue demonstrated increased 19-OH-DOC production (a 19-nor-DOC precursor) which may have been responsible for the 19-nor-DOC excess. We hypothesize that compressive adrenal damage from the cyst may produce a form of adrenal regeneration hypertension which is known to be associated with 19-nor-DOC excess.
CT is the imaging procedure of choice for the detection of most suspected adrenal masses. But except for some patients with acute adrenal hemorrhage or fat-containing myelolipoma, the precise histologic nature of an adrenal mass is not apparent from the CT image. MIBG radionuclide scanning is useful in some patients with pheochromocytoma, whereas bilateral adrenal venous sampling for hormone assay is necessary for correct lateralization in some patients with a small aldosterone-producing adenoma. The potential value of MR imaging in the characterization of adrenal masses, especially to distinguish benign adrenal cortical adenomas from metastatic disease, is now under investigation. Currently percutaneous aspiration biopsy is still necessary to make this distinction in patients with an adrenal mass and a known extra-adrenal primary neoplasm.
A case of an epithelial-lined (true) adrenal cyst is reported. Although over 300 adrenal cysts have been reported in the literature, true cysts are rare. In this case, a 4.0 cm cyst lined by cuboidal to flattened cells with bland cytologic features was incidentally found at autopsy. Immunologic studies performed on formalin-fixed, paraffin-embedded sections demonstrated that the cells expressed keratins (AE1/AE3+, CAM 5.2+, and MAK-6+) and were negative for epithelial membrane antigen, vimentin, factor VIII, and desmin. Normal adrenal cortical and medullary cells did not express keratins, suggesting that the cyst lining was not derived from either adrenal cortex or medulla. A mesothelial origin, with a pathogenesis analogous to the formation of primary cysts of the spleen, is proposed.
Adrenal pseudocysts are cystic lesions arising within the adrenal gland surrounded by a fibrous tissue wall devoid of a recognizable lining layer. This study comprised eight adrenal pseudocysts surgically excised at the Massachusetts General Hospital. The median age of the patients was 41 years. Seven of the eight individuals were women. There was no apparent etiologic relationship to prior trauma or pregnancy. Half of the patients described symptoms that resolved following pseudocyst removal. The remaining individuals were asymptomatic with adrenal pseudocysts discovered incidentally during the work up of other medical problems. Adrenal pseudocyst size ranged from 1.8 to 10 cm. Pseudocyst size did not correlate with the presence of symptoms. The histologic and immunohistochemical findings in this study suggest that at least some adrenal pseudocysts are of vascular origin. In two lesions, small foci of residual cells lining the inner pseudocyst wall were found that expressed factor VIII antigen (also Ulex Europaeus lectin in one case) but not vimentin, keratin, or epithelial membrane antigen. In both cases, abundant elastic tissue was present in the pseudocyst wall, and in one lesion, adrenal vein smooth muscle was present as well. In both cases, dilated sinusoids were found at the periphery of the pseudocysts and, in one lesion, the sinusoids appeared to coalesce to form the pseudocyst cavity. In the majority of the remaining six cases there was also some histologic evidence to suggest a vascular origin. In five and three cases, respectively, abundant elastic tissue and adrenal vein smooth muscle were found within the pseudocyst wall. In two lesions, both elastic tissue and smooth muscle were present. In addition, adrenal sinusoids were prominently dilated at the periphery of four pseudocysts and, in one case, the sinusoids appeared to coalesce to form the pseudocyst cavity.
We report a case of a feminizing adrenocortical adenoma in a 8-year-old boy and feminizing carcinoma in a 25-year-old man. Because diagnosis of adrenal malignancy in such tumors by histopathological criteria is not always conclusive, a clinicoradiological approach may be used in the evaluation.
We reviewed 106 cases of adrenal masses of all types in all age groups. Thirty-three contained calcium visible on radiographs, sonography, or computed tomography (CT). Neuroblastoma was the most common calcified adrenal mass (10 cases), and occurred only in children. Adrenal cyst (6 cases) was the most common calcified adrenal mass in adults. Other calcified adrenal masses included 5 cortical adenomas, 4 adrenal carcinomas, 3 cases of adrenal hemorrhage, 2 adrenal metastases, 2 pheochromocytomas, and 1 histoplasmoma. Calcification within an adrenal mass is therefore nonspecific. All the adrenal cysts had a characteristic radiographic pattern, showing only peripheral curvilinear calcification. The presence and pattern of calcium in an adrenal mass must be correlated with other imaging features (e.g., size, homogeneity, enhancement pattern, margination) to allow correct differential diagnosis. This can best be done by CT.
Computed tomography is the preferred imaging modality for adrenal lesions, particularly pheochromocytoma. Central hemorrhagic degeneration of a pheochromocytoma can cause the mass to resemble a benign adrenal cyst. Such a case is illustrated and the preoperative evaluation discussed.
Four patients with adrenal cysts have recently been treated at the Urology Service of this center. Presentation, diagnostic evaluation, and treatment are described, and the literature regarding frequency of presentation, symptoms, and diagnostic differential is reviewed.
Clinical and radiographic data of an unusual case of calcification in a benign adrenaltumor are presented. Selective arteriography and venography as well as histologic examination revealed a cystic adenoma with areas of calcification, hemorrhage, and necrosis.
A case of both adrenal myelolipoma and adenoma is presented. The diagnosis of myelolipoma was suggested preoperatively by computed tomography in which one of the masses had negative attenuation coefficients.
A case of adrenocortical adenoma containing small adipose foci is presented. A small amount of fat within the mass led to an erroneous preoperative diagnosis of myelolipoma. Adrenal adenoma should be included in the differential diagnosis of adrenal mass containing fat.
This study evaluated the usefulness of dynamic MRI to differentiate various adrenal tumours.
Sixty-five adrenal tumours (28 adenomas, 22 metastases, seven phaeochromocytomas, five neurogenic tumours and three tuberculous granulomas) were evaluated with gadolinium-enhanced dynamic MRI (13 at 0.5 T, 52 at 1.5 T). In this technique, a series of 12 sequential images (gradient-echo images at 0.5 T and spin-echo images at 1.5 T) were obtained up to 21 min after bolus administration of 0.1 mmol/kg Gd-DTPA.
All 28 adenomas showed peak enhancement in the early phase (< 2 min) and quick washout. Fourteen of 22 metastases showed peak enhancement in the early or middle phase (< 9 min) and slow washout. Six of seven phaeochromocytomas revealed marked peak enhancement in the early phase and little washout. All neurogenic tumours showed gradually increasing enhancement. Granulomas showed little enhancement. As a result, only 14 adrenal masses (27/65, 42%) were correctly classified according to contrast enhancement patterns. However, if we consider each type of enhancement pattern to be specific to adenoma, metastasis, phaeochromocytoma, neurogenic tumour and tuberculous granuloma respectively, 56 of the 65 adrenal masses (86%) could be classified. Seven of the indistinguishable nine tumours were performed at 0.5 T system using gradient-echo sequences.
Dynamic MR imaging at 1.5 T is useful in the differentiation of adrenal masses. Imaging at 0.5 T with gradient-echo sequences seems less useful to distinguish adenomas from metastases.
We report the case of a spontaneously ruptured adrenal adenoma which caused Cushing's syndrome. The 34-year-old female patient had severe left-side back pain and anemia. Computerized tomography disclosed a retroperitoneal hemorrhage and a 4-cm mass on the left which was considered to be an adrenal tumor. An operation was successfully performed, and the patient is well 12 months after surgery.
We report the first case of benign aldosteronoma of an ordinary size with calcifications. We review the clinical, clinical imaging, histopathological, and laboratory features of aldosterone-producing adrenal adenoma versus carcinoma. We conclude that no single feature is diagnostic, and the full range of data must be considered. Calcifications may not necessarily be a distinguishing point.
Incidentally discovered adrenal masses are fairly common, although there are some controversies concerning the results of hormonal investigation (especially DHEAS values) and the methods of management. We summarize our experience in diagnosis, pathological findings and treatment of a large group of patients with incidentally found adrenal tumours.
Our study included patients referred to the Department of Endocrinology of the Centre of Post-graduate Medical Education (Warsaw, Poland) during the last 10 years because of an adrenal tumour incidentally found on ultrasound scan. In all cases this was confirmed by computed tomography. There were 208 patients (148 female and 60 male), 14-76 years old. Unilateral adrenal masses were found in 172 patients (right 106, left 66), while bilateral masses were demonstrated in 36 patients. The size of the tumours ranged between 0.8 and 21.0 cm. The most common clinical abnormalities were hypertension (36 cases), obesity (23 cases), diabetes (8 cases), Addison's disease (6 cases).
Endocrine tests evaluating pituitary-adrenal function (urinary excretion of 17-hydroxycorticosteroids, 17-ketosteroids and catecholamines, plasma concentrations of ACTH, cortisol, DHEAS, androstendione and testosterone, dexamethasone suppression test and corticotrophin-releasing hormone stimulation test).
Cortisol hypersecretion was noted in two patients with coexisting Cushing's disease and high normal 17-OHCS values with lack of dexamethasone suppressibility were found in six other patients with pre-clinical Cushing's syndrome. More common were subtle hormonal abnormalities: low ACTH levels (in 33 out of 98 investigated patients), diminished dexamethasone suppressibility and lack of ACTH response in the CRH test (in two out of 12 patients). Urinary catecholamine excretion was elevated in nine patients. In the group of 85 patients treated by surgery the most frequent pathological findings were: adrenocortical adenoma (21), carcinoma (17), phaeochromocytoma (13), metastatic masses (12) and myelolipoma (10). The size of carcinomas ranged from 3.2 to 20.0 cm, while the size of non-malignant tumours ranged from 1.5 to 21.0 cm.
Every patient with an incidentally discovered adrenal mass has to be investigated to detect malignancy and subtle hormonal overproduction, to select the cases for surgical treatment. Most of the adrenocortical carcinomas were > 7.0 cm in diameter. For prophylactic purposes, adrenal incidentalomas > 4.0 cm should be treated by surgery, while the smaller ones could be followed-up (with special care for those between 3.0 and 4.0 cm).