[437] Peripancreatic Paragangliomas: A Potential Diagnostic Pitfall in Cytopathology and Surgical Pathology.

Aatur D Singhi, Ralph H Hruban, Johji Imura, Richard Schulick, Christopher Wolfgang, Syed Z Ali. The Johns Hopkins Medical Institutions, Baltimore, MD; Dokkyo University School of Medicine, Mibu, Tochigi, Japan

Background: Paragangliomas (PGs) or extra-adrenal pheochromocytomas are uncommon neoplasms arising in paraganglia and plexuses of the autonomic nervous system. In rare instances, PGs present around and involve the pancreas, mimicking a primary pancreatic lesion. We have collected a series of peripancreatic PGs clinically simulating a primary pancreatic lesion and discuss their clinical and pathologic features.
Design: Review of the cytopathology and surgical pathology archives at our institution between 1997 to 2010 identified 8 cases of peripancreatic PGs. Fine needle aspirates (FNA) and surgical pathology resections were reviewed for all cases. Demographic and follow-up information was also obtained.
Results: The cases consisted of 4 men and 4 women with an age range of 37 to 78 years (mean, 51 years). Patients presented clinically with either abdominal pain (5/8, 63%) or an incidental mass (3/8, 37%) discovered on routine radiographic imaging. All patients were found to have mass lesions suspicious for a primary pancreatic neoplasm on radiographic examination. The lesions were predominantly located in the body of the pancreas (5/8, 63%) and ranged in size from 5.1 to 17 cm (mean 10.9 cm). Five of 8 (63%) cases also demonstrated cystic change. FNA was performed in 5 cases. The diagnostic accuracy of FNA was low with 3 of 5 (60%) cases misdiagnosed as: pancreatic endocrine neoplasm (PEN) [n=1], retroperitoneal sarcoma [n=1] or pseudocyst [n=1]. In addition, 2 of 8 (25%) resection specimens were misdiagnosed as PEN. Immunohistochemistry was performed on all cases confirming the characteristic 2-cell populations. Follow-up information was available for all patients ranging from 2 months to 11.6 years (mean, 3 years). Two patients (25%) developed metastatic disease with multiple organ metastases and died 2.8 and 4.6 years after diagnosis.
Conclusions: Peripancreatic PGs are extremely rare tumors that may be mistaken for primary pancreatic lesions. In unsuspecting cases, the interpretation of FNA and surgical pathology resections can be diagnostically challenging. Awareness and proper recognition of this entity are imperative in ensuring proper patient management. Further, close follow-up of these cases should be considered due to the possibility of metastatic disease.
Category: Cytopathology

Tuesday, March 1, 2011 9:30 AM

Poster Session III # 68, Tuesday Morning

 

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