Pancreatic paraganglioma: An extremely rare entity and crucial role of immunohistochemistry for diagnosis.

Paragangliomas are rare neuroendocrine neoplasms arising in extra-adrenal chromaffin cells of autonomic nervous system and histologically akin to chemodectomas. They are rare, affecting about 1 in 2,000,000 population. It is a generic term applied to tumors of paraganglia regardless of the location. In rare instances, paragangliomas present around and involve the pancreas, thereby mimicking any one of the more common primary pancreatic lesions. Pancreatic paraganglioma is an extremely rare tumor. It grows slowly, so radical resection is recommended to achieve curability with good prognosis. These neoplasms present considerable diagnostic difficulty not only for the clinician and radiologist but also for the pathologist. Here, we report a case of a 55-year-old woman who presented with a left-sided abdominal swelling for 3 months duration, initially having clinical suspicion of an ovarian tumor. The radiological imaging revealed a lesion in the tail of pancreas with a differential diagnosis of pancreatic carcinoma and metastatic tumor. Only after exploratory laparotomy, the diagnosis was made as a rare case of pancreatic paraganglioma on the basis of histological examination and immunohistochemistry.