[Case of paraganglioma mimicking lymph node metastasis from a pancreatic neuroendocrine neoplasm].

A 79-year-old woman with a history of hypertension presented with lumbago. Magnetic resonance imaging revealed a retroperitoneal mass. Computed tomography revealed another contrast-enhanced mass in the pancreatic tail. We performed endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) of the pancreatic mass and diagnosed it as a pancreatic neuroendocrine neoplasm (PanNEN). The retroperitoneal mass was thought to be lymph node metastases of the PanNEN. During surgical resection, severe hypertension occurred when the retroperitoneal mass was manipulated. The pathological diagnosis was a G1 neuroendocrine tumor of the pancreatic tail and a paraganglioma. Neuroendocrine neoplasms and paraganglioma demonstrated similar findings on imaging studies. However, FNA of a paraganglioma puts the patient at risk of severe hypertension. We suggest differentiating between PanNEN and paraganglioma before EUS-FNA.