Prognostic indicators of malignancy in adrenal pheochromocytomas: clinical, histopathologic, and cell cycle/apoptosis gene expression analysis.
ABSTRACT Pheochromocytomas are malignant in approximately 10% of patients. The histologic differentiation between benign and malignant tumors is difficult, the latter diagnosed by the presence of metastatic disease or recurrence.
To determine if postoperative histologic evaluation using the previously proposed Pheochromocytoma of the Adrenal Gland Scaled Score (PASS) and cell cycle/apoptosis markers can predict patients at risk for recurrence.
Using the Memorial Sloan-Kettering Cancer Center adrenal database, we identified 48 patients with 51 resected pheochromocytomas (1987-2006). A senior endocrine pathologist, blinded to clinical outcome, reviewed the histopathologic characteristics of all cases using the PASS system. This pheochromocytoma scoring system is based on the presence of 12 different histologic parameters, including tumor necrosis, mitotic rate, tumor cell spindling, and the presence of large cell nests. In addition, we constructed a tissue microarray of all 5 malignant tumors and 41 of the benign tumors. By immunostaining of the tissue microarray, we assessed the expression of 7 different cell cycle/apoptosis-related genes (p53, Ki-67, Bcl-2, mdm-2, cyclin D1, p21, and p27).
Forty-three patients had a benign clinical course while 5 patients harbored a clinically malignant pheochromocytoma. Tumor necrosis (focal or confluent) was a particularly powerful indicator of malignancy present in 4 of 5 patients (80%) with malignant tumors, but only in 3 of 42 cases (7%) with benign neoplasms (P = .0009). The presence of a high mitotic rate (>3/10 high power fields) and tumor cell spindling significantly correlated with malignancy (P = .026 and .041, respectively). High cellularity was more often present in the malignant lesions (P = .050). There was a highly significant difference in PASS scores between benign and malignant cases (P = .0003). All malignant pheochromocytomas had a PASS score >/=6, well above the previously proposed >/=4 cutoff value. Two of the 4 patients testing positive for Ki-67 (>2% nuclear staining) had a clinically malignant course while only 3 (7%) of the 41 cases with lower Ki-67 positivity rate behaved in a malignant fashion (P = .055). Ki-67-positive tumor had a significantly higher chance of harboring tumor necrosis than Ki-67-negative neoplasms (P < .01). There was no difference in staining between benign and malignant pheochromocytomas using p53, Bcl-2, mdm-2, cyclin D1, p21, and p27.
(1) A PASS score of <4 predicted benign pheochromocytomas. (2) All malignant pheochromocytomas had a PASS score >/=6, which was significantly higher compared with the benign lesions. Patients with a PASS score >/=4 should be followed closely for recurrence. (3) p53, Bcl-2, mdm-2, cyclin D1, p21, and p27 appear to have no role in predicting the behavior of pheochromocytomas. Ki-67 may help identify those neoplasms at risk for recurrence by prompting the pathologist to look aggressively for adverse histologic features.
Article: Updated and new perspectives on diagnosis, prognosis, and therapy of malignant pheochromocytoma/paraganglioma.[show abstract] [hide abstract]
ABSTRACT: Malignant pheochromocytomas/paragangliomas are rare tumors with a poor prognosis. Malignancy is diagnosed by the development of metastases as evidenced by recurrences in sites normally devoid of chromaffin tissue. Histopathological, biochemical, molecular and genetic markers offer only information on potential risk of metastatic spread. Large size, extraadrenal location, dopamine secretion, SDHB mutations, a PASS score higher than 6, a high Ki-67 index are indexes for potential malignancy. Metastases can be present at first diagnosis or occur years after primary surgery. Measurement of plasma and/or urinary metanephrine, normetanephrine and metoxytyramine are recommended for biochemical diagnosis. Anatomical and functional imaging using different radionuclides are necessary for localization of tumor and metastases. Metastatic pheochromocytomas/paragangliomas is incurable. When possible, surgical debulking of primary tumor is recommended as well as surgical or radiosurgical removal of metastases. I-131-MIBG radiotherapy is the treatment of choice although results are limited. Chemotherapy is reserved to more advanced disease stages. Recent genetic studies have highlighted the main pathways involved in pheochromocytomas/paragangliomas pathogenesis thus suggesting the use of targeted therapy which, nevertheless, has still to be validated. Large cooperative studies on tissue specimens and clinical trials in large cohorts of patients are necessary to achieve better therapeutic tools and improve patient prognosis.Journal of Oncology 01/2012; 2012:872713.
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ABSTRACT: Pheochromocytomas are tumours arising from chromaffin tissue located in the adrenal medulla associated with typical symptoms and signs which may occasionally develop metastases, which are defined as the presence of tumour cells at sites where these cells are not found. This retrospective analysis was focused on clinical, genetic and histopathologic characteristics of primary metastatic versus primary benign pheochromocytomas. We identified 41 subjects with metastatic pheochromocytoma and 108 subjects with apparently benign pheochromocytoma. We assessed dimension and biochemical profile of the primary tumour, age at presentation and time to develop metastases. Subjects with metastatic pheochromocytoma presented at a significantly younger age (41·4 ± 14·7 vs. 50·2 ± 13·7 years; P < 0·001) with larger primary tumours (8·38 ± 3·27 vs. 6·18 ± 2·75 cm; P < 0·001) and secreted more frequently norepinephrine (95·1% vs. 83·3%; P = 0·046) compared to subjects with apparently benign pheochromocytomas. No significant differences were found in the incidence of genetic mutations in both groups of subjects (25·7% in the metastatic group and 14·7% in the benign group; P = 0·13). From available histopathologic markers of potential malignancy, only necrosis occurred more frequently in subjects with metastatic pheochromocytoma (27·6% vs. 0%; P < 0·001). The median time to develop metastases was 3·6 years with the longest interval 24 years. In conclusion, regardless of a genetic background, the size of a primary pheochromocytoma and age of its first presentation are two independent risk factors associated with the development of metastatic disease.European Journal of Clinical Investigation 04/2011; 41(10):1121-8. · 3.02 Impact Factor
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ABSTRACT: Paraganglioma is a malignant tumor that arises from the extra adrenal paraganglionic cells of the sympathetic or parasympathetic systems. Herein, we present a case of abdominal mass of unknown histology that underwent a very difficult surgical mass resection. Its final histologic diagnosis was non-functional paraganglioma that was presented as a huge intra-peritoneal mass. The patient was a 55-year-old Iranian lady who referred to our center with a giant abdominal mass. Fine needle aspiration (FNA) biopsy showed undifferentiated carcinoma. After laparotomy for mass resection pathology evaluation revealed; malignant paraganglioma, non-metastatic type. Further post-operative patients evaluations showed that the tumor was sporadic in nature and the subsequent patient's natural history was uneventful. Pathologic evaluations have key roles in the exact diagnosis of abdominal masses with unidentified sources. For the paragangliomas, all of them should be regarded malignant until proved otherwise. However, combined use of biochemical markers, immunohistochemical techniques (IHC), and genetic analysis have key roles in the diagnosis and treatment of paragangliomas. Additionally, surgical removal is the proved curative way of paraganglioma treatment. Asymptomatic intra-peritoneal paraganglioma is very rare, especially its malignant variety. This case emphasizes that full pathologic investigation would reveal the exact nature of idiopathic abdominal masses, especially in the state of absence of typical clinical and para-clinical symptoms.International journal of surgery case reports. 07/2012; 3(11):537-40.