[Show abstract][Hide abstract] ABSTRACT: Gastric neuroendocrine carcinomas (NEC) are very rare, aggressive tumors of the stomach that are distinct from the more benign neuroendocrine tumors, sometimes referred to as "gastric carcinoids." We present 3 cases of gastric NEC representing various histological subtypes that were successfully staged and followed with F-FDG PET/CT, impacting therapeutic management in each case.
Full-text · Article · May 2013 · Clinical nuclear medicine
[Show abstract][Hide abstract] ABSTRACT: A wide variety of malignant renal and urinary bladder diseases can be detected on (18)F-FDG PET/CT. Although the PET/CT findings are often nonspecific, the aim of this atlas was to demonstrate that the spectrum of renal and urinary bladder malignancy that can be evaluated with PET/CT is much broader than current medical literature would suggest. PET/CT readers and oncologists should be aware of the variety of urological tumor types that can be detected on PET/CT and some of the patterns of (18)F-FDG uptake that can be observed in these cases.
[Show abstract][Hide abstract] ABSTRACT: A wide variety of malignant gastric diseases can be detected, staged, and followed on (18)F-FDG PET/CT. Although the PET/CT findings are often nonspecific and some can be seen in certain benign gastric diseases, the aim of this atlas was to demonstrate that the wide histological spectrum of gastric tumors that can be evaluated, staged, and followed with PET/CT is much broader than current medical literature would suggest. PET/CT readers and oncologists should be aware of the utility of PET/CT in these tumors and the imaging characteristics and patterns of (18)F-FDG uptake that can be demonstrated in these cases.
[Show abstract][Hide abstract] ABSTRACT: Sarcomatoid carcinomas of the lung account for less than 0.4% of all lung tumors, and they are a heterogeneous group of non-small-cell lung carcinomas containing a sarcoma or sarcoma-like component. They have a poor prognosis, with an overall 5-year survival of 25% compared with 45% for other types of non-small-cell lung carcinomas. The literature on the use of F-FDG PET/CT to stage these tumors is very limited, and their PET/CT imaging characteristics have not been previously described. We report on 2 cases of sarcomatoid carcinoma that resembled malignant pleural mesothelioma on F-FDG PET/CT and were correctly staged.
Full-text · Article · Apr 2012 · Clinical nuclear medicine
[Show abstract][Hide abstract] ABSTRACT: A 66-year-old man, who presented with bright red blood per rectum, was referred for an 18 F-FDG PET/CT after colonoscopy showed two suspicious colon masses, which were biopsied to reveal an adenocarcinoma of unknown origin. PET/CT showed two intensely FDG-avid colon masses as well as an unsuspected FDG-avid lung mass, which was biopsied to reveal a primary lung adenocarcinoma. Immunohistochemistry confirmed the two colon metastases were of pulmonary origin. It is extremely rare for lung carcinoma to present with symp-tomatic colon metastases, with only 11 cases described in the literature. We report the first case of the utility of 18 F-FDG PET/CT in staging a patient who presented with symptom-atic colon metastases of an unknown primary lung malig-nancy.
Full-text · Article · Dec 2011 · Nuclear Medicine and Molecular Imaging
[Show abstract][Hide abstract] ABSTRACT: Bilateral renal masses are uncommon but can raise a strong suspicion of primary or secondary malignan-cy, especially during the initial work-up of an oncology patient. Renal oncocytomas are benign renal tumors that are commonly discovered incidentally on diagnostic imaging with a small percentage occurring bilaterally. Although 18 F-FDG uptake in renal oncocytomas has been described, a case of a bilateral 18 F-FDG-avid renal oncocytoma has not been previously reported in the literature. A variety of malignant causes of bilateral 18 F-FDG positive renal masses are known, however it is important to include this benign etiology in the differential diagnosis. We report an unusual case of an incidental bilateral renal oncocytoma evaluated with contrast enhanced CT and 18 F-FDG PET/CT.
Full-text · Article · Dec 2011 · Nuclear Medicine and Molecular Imaging
[Show abstract][Hide abstract] ABSTRACT: Progressive transformation of germinal centers (PTGC) is a benign reactive adenopathy that leads to abnormal nodal enlargement. Although not believed to be premalignant, recent genetic studies have found evidence linking PTGC to Hodgkin lymphoma. In this case of a 14-year-old girl referred for an F-18 FDG PET/CT, extensive FDG-avid lymphadenopathy that was suspicious for lymphoma, was confirmed to be PTGC on biopsy. A follow-up PET/CT showed significant resolution of FDG-avid disease. As a new understanding of a possible link between PTGC and Hodgkin lymphoma emerges, serial PET/CT imaging may play a prominent role in the staging and follow-up of PTGC.
Full-text · Article · Oct 2011 · Clinical nuclear medicine
[Show abstract][Hide abstract] ABSTRACT: A 26-year-old man with a prior history of acute leukemia that was treated with a stem cell transplant (SCT) was referred for an F-18 FDG PET/CT to assess suspicious new gastric mucosal lesions. The lesions were FDG-avid and were histologically proven to be acute lymphoblastic leukemia (ALL). Extramedullary relapse of ALL after SCT is very rare, with only 60 cases reported in the literature, and the role of F-18 FDG PET/CT in monitoring for ALL relapse following SCT has not been previously investigated. This rare case report highlights the use of F-18 FDG PET/CT in staging gastric relapse of ALL following SCT.
Full-text · Article · Aug 2011 · Clinical nuclear medicine
[Show abstract][Hide abstract] ABSTRACT: A previously healthy 27-year-old woman presented with a thyroid goiter, symptoms of thyrotoxicosis, and mild respiratory obstruction. The serum thyroid stimulating hormone (TSH) was suppressed, serum T4 was elevated, and 24-hour radioiodine uptake was elevated at 59%. Thyroid scintigraphy showed intense uptake in an enlarged gland, with a cold nodule on the right, and a large isolated mass in the mediastinum, with very mild uptake. Total thyroidectomy and excision of the mediastinal mass revealed multiple pathologies: Graves disease in the thyroid gland with an incidental papillary thyroid carcinoma, and a benign sequestered intrathoracic multinodular goiter. Thyroid carcinoma can develop in a gland affected by Graves disease, however, the presence of concomitant sequestered intrathoracic thyroid tissue unaffected by Graves disease is highly unusual and has not been previously described. We present the scintigraphic findings, and several theories that could help explain these findings.
Full-text · Article · Feb 2011 · Clinical nuclear medicine
[Show abstract][Hide abstract] ABSTRACT: A 64-year-old man with high-grade follicular lymphoma had a staging F-18 FDG PET/CT scan, which showed extensive disease in the lymph nodes, skeleton, and spleen. After 5 cycles of chemotherapy, a post-therapy PET/CT showed resolution of all abnormal findings except for 1 lesion in the neck. Biopsy revealed a Hurthle cell thyroid carcinoma. This unexpected second primary malignancy, although present on the initial scan, revealed itself visually only on the post-therapy PET/CT. It is important to carefully evaluate post-therapy PET/CT scans especially in cases of "mixed" or "discordant" metabolic response, as presumed residual disease may represent the unmasking of another primary malignancy.
Full-text · Article · Nov 2010 · Clinical nuclear medicine
[Show abstract][Hide abstract] ABSTRACT: A 64-year-old man with a history of smoking and asbestos exposure was referred for an F-18 FDG PET/CT, to evaluate multiple growing lung nodules that had been found incidentally on prior chest CTs. The PET/CT showed multiple hypermetabolic nodules in both the lungs, with varying intensity of FDG uptake, raising the suspicion of multifocal malignancy. Wedge resections of the right lung were done to remove the 2 most hypermetabolic nodules, and histologic evaluation revealed pulmonary light and heavy chain deposition disease. A follow-up PET/CT performed 1 year later showed another slowly growing nodule in the left lung with a significant increase in F-18 FDG uptake. Only 22 cases of pulmonary light chain deposition disease have been reported in the literature. This is a report of F-18 FDG uptake in nodules of pulmonary light chain deposition disease. These nodules can grow in size and can show increased F-18 FDG uptake on follow-up studies, mimicking a growing lung malignancy.
Full-text · Article · Aug 2010 · Clinical nuclear medicine
[Show abstract][Hide abstract] ABSTRACT: Extraosseous osteosarcomas account for less than 5% of all osteosarcomas. Primary osteosarcoma of the thyroid is a very rare tumor, with only 28 cases described in the published data. This is a case of a 40-year-old woman, 3 months postpartum, who presented with a rapidly growing mass in the neck, causing airway obstruction. An F-18 FDG PET-CT showed a large intensely FDG-avid mass in the thyroid gland, which was histopathologically confirmed to be a primary thyroid osteosarcoma. The patient was treated with tracheostomy, radiation therapy, and 2 cycles of chemotherapy. A posttherapy F-18 FDG PET-CT scan showed that the thyroid osteosarcoma was responding to therapy; however, the patient had developed new lung metastases.
Full-text · Article · Jul 2010 · Clinical nuclear medicine
[Show abstract][Hide abstract] ABSTRACT: Primary cardiac tumors are rare, and of these, primary cardiac lymphomas account for less than 1%. Most are B-cell non-Hodgkin lymphomas, and the right atrium and right ventricle are the most frequently involved sites. The clinical presentation varies, but commonly involves pericardial effusions, AV block, valvular dysfunction, or heart failure. We present a 72-year-old man who was referred for an F-18 FDG PET-CT scan to evaluate a cardiac mass. An intensely hypermetabolic mass was observed replacing most of the right ventricle, which was confirmed with a contrast-enhanced CT as well as magnetic resonance imaging. Endomyocardial biopsy revealed a low-grade T-cell lymphoma. This is a rare report of a cardiac T-cell lymphoma imaged with F-18 FDG PET-CT.
Full-text · Article · May 2010 · Clinical nuclear medicine
[Show abstract][Hide abstract] ABSTRACT: The aims of this study are to evaluate the sensitivity of FDG PET/CT for detection of soft tissue and osseous sarcomas on the basis of FDG avidity.
We retrospectively evaluated 212 consecutive patients with known soft tissue or osseous sarcoma who had undergone a FDG PET/CT study for the initial staging or assessment of recurrence of disease. The maximum standardized uptake value (SUVmax) of each primary and/or most intense metastatic lesion was measured and compared with the histological data provided in the final pathological reports. An SUVmax of 2.5 or greater was considered positive for our analysis.
Sufficient histopathological data were available for 160 soft tissue sarcomas and 52 osseous sarcomas. FDG PET/CT detected 93.9% of all sarcomas with a sensitivity of 93.7% for soft tissue sarcomas and 94.6% for osseous sarcomas. The sensitivities of the most common sarcoma histologies were 100% for leiomyosarcomas, 94.7% for osteosarcomas, 100% for Ewing's sarcomas, 88.9% for liposarcomas, 80.0% for synovial sarcomas, 100% for gastrointestinal stromal tumors, 87.5% for malignant peripheral nerve sheath tumors, 100% for fibroblastic and myoblastic sarcomas, and 100% for malignant fibrohistiocytic tumors. The receiver-operating characteristic curve revealed an area under the curve of 94% for the discrimination of low-grade and high-grade sarcomas imaged for initial staging by FDG PET/CT.
The combined metabolic and morphological information of FDG PET/CT imaging allows high sensitivity for the detection of various sarcomas and accurate discrimination between newly diagnosed low-grade and high-grade sarcomas.
No preview · Article · Aug 2009 · European Journal of Nuclear Medicine