Malignant extra-adrenal pancreatic paraganglioma: case report and literature review.

BACKGROUND: Pancreatic paragangliomas are rare tumors, with only 16 reported cases to date. One of these cases demonstrates metastasis to lymph node, while another case was functional, however, none of these cases showed malignant and large, pancreatic paraganglioma with marked invasion. Also another unique feature was the age of our patient compared to the average reported ages in published literature (42-85 years).

CASE PRESENTATION: A 19-year-old woman presented with a one-year history of intermittent abdominal pain. Physical examination showed a palpable mass in the right upper abdomen, but initial laboratory results were within normal ranges; tumor markers (CEA, AFP, and CA19-9) were negative. An abdominal and pelvic computed tomography (CT) scan showed a well-defined retroperitoneal para-aortic mass. The CT scan revealed that the surrounding lymph nodes were not enlarged, but the liver showed evidence of parenchymal infiltration. Intraoperatively, a large, firm tumor originating from the head of pancreas was found pushing on the caudate hepatic lobe and the inferior vena cava (IVC). The tumor was resected through a pancreaticoduodenectomy, involving segment VI of the liver and a small segment of the IVC. The blood pressure spiked (>220 mm Hg) when the tumor was manipulated during the operation. The final pathology report showed a 9-cm tumor with lymphovascular invasions; immunohistochemistry was positive for synaptophysin and chromogranin. All resection margins were negative and 1/15 lymph nodes was positive for metastasis. Post-operative recovery was unremarkable. One month after discharge, the patient was re-admitted with abdominal pain and found to have an abdominal collection at the resection site, which was drained under CT guidance. She received a therapeutic dose of I131-metaiodobenzylguanidine (MIBG). Follow-ups showed the absence of recurrence, and she has remained disease free.

CONCLUSION: This patient was an extraordinary example of a rare tumor. Even more remarkable was that the tumor was malignant with lymph node invasion. To our knowledge, a case similar to that presented here has not been previously reported in the literature.