Purely cystic neuroendocrine tumor: a case report

Abstract

Cystic pancreatic neuroendocrine tumors (PNET) are relatively rare. We report a patient with a purely cystic PNET. A 61-year-old woman presented with lower abdominal pain. Computed tomography (CT) scan showed a 30-mm cystic lesion with a well-defined, thin enhancing peripheral rim in the pancreatic head without a solid component. The slightly high density on CT scan and hyperintensity on magnetic resonance imaging with T2-weighted imaging showing a fluid-fluid level in the cystic lesion were consistent with a bloody component. Contrast-enhanced endoscopic ultrasound using Sonazoid^® revealed a 2-mm cyst wall with early enhancement. Following a diagnosis of cystic PNET, pylorus-preserving pancreaticoduodenectomy was performed. The resected specimen showed a 32-mm cystic tumor with bloody content and a capsule. Immunohistochemical analysis revealed positive staining for chromogranin and synaptophysin. The Ki-67 index was <2%. The final diagnosis was nonfunctioning PNET grade 1.