Castleman Disease Misdiagnosed as Pancreatic Neuroendocrine Tumor by Fine Needle Aspiration Biopsy.

Castleman disease (CD) is a lymphoproliferative disorder that rarely occurs in the pancreas. We reported a 46-year-old man was admitted to our hospital due to recurrent minor epigastric pain for 7 days. The abdominal enhanced CT showed irregular foci in the body of the pancreas with abundant blood supply considered a neuroendocrine tumor. The patient was subsequently diagnosed with pancreatic neuroendocrine tumor by an ultrasound-guided fine needle aspiration biopsy. Therefore, he underwent an open pancreatic mass resection. The ultimate diagnosis was CD and belonged to hyaline vascular type based on the postoperative pathology. After a 13-month follow-up, no recurrence of abdominal pain or lesions was observed. This case suggests that fine needle aspiration biopsy is not conclusive and unsuitable for pancreatic CD and highlights the importance of routine pathology due to the absence of typical signs and symptoms.