Pancreatic body adenocarcinoma with neuroendocrine tumor characteristics: A case report

A 61-year-old female with pancreatic body cancer underwent a distal pancreatectomy. The tumor was a moderately- to poorly-differentiated adenocarcinoma. Tumor growth filled the dilated main pancreatic duct (MPD) and infiltrated the surrounding area. Six months later, metastases to the left diaphragm and MPD of the remnant pancreatic head were detected. Chemoradiotherapy was administered, but the patient succumbed 22 months after surgery. An autopsy demonstrated that a moderately- to poorly-differentiated adenocarcinoma had arisen from the pancreatic head and infiltrated the duodenum and bile duct. Huge liver metastases and multiple peritoneal disseminations were also present. Microscopically, a portion of the tumor had a pseudo-rosette appearance in the adenocarcinoma component, while another section showed characteristics of a neuroendocrine tumor (NET) immunohistochemically. The original surgically-resected tumor also showed NET characteristics immunohistochemically. It is therefore necessary to search for NET components in pancreatic cancer with atypical growth and metastases, even when adenocarcinoma has been diagnosed histologically.