Mixed neuroendocrine non-neuroendocrine neoplasm: a case report and review.

Mixed neuroendocrine non-neuroendocrine neoplasm (MiNEN) of the pancreas is a rare entity, and obtaining a preoperative diagnosis is difficult. We present a 70-year-old man in whom the possibility of MiNEN was successfully discovered preoperatively by endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA). Immunostaining revealed positive results for the neuroendocrine markers chromogranin A and synaptophysin.