Solid Serous Cystadenoma Mimicking Neuroendocrine Tumor of the Pancreas: A Case Report.

Solid-type serous cystadenoma (SSCA) of the pancreas is an extremely rare benign condition among pancreatic cystic neoplasms. Although the imaging characteristics are not pathognomonic, this entity may mimic other solid pancreatic tumors. In particular, it can closely resemble a pancreatic neuroendocrine neoplasm (pNEN) on radiologic studies. We report the case of a 67-year-old woman who presented with abdominal pain. Preoperative abdominal magnetic resonance imaging (MRI) with contrast demonstrated a solid, hypervascular lesion at the pancreas, measuring 3.5 × 2.2 × 1.9 cm, with marked enhancement on dynamic imaging. A nonfunctioning pancreatic neuroendocrine tumor was initially suspected. The patient underwent laparoscopic pancreaticoduodenectomy. Histopathologic examination revealed a solid variant of serous cystadenoma, a rare subtype of pancreatic cysts. The patient remains asymptomatic, with no evidence of recurrence or residual disease at 7 years postoperatively. This case highlights the diagnostic challenge of distinguishing solid-type serous cystadenomas from other pancreatic lesions based on imaging alone, underscoring the role of pathology in definitive diagnosis.