Adenocarcinoma with extensive neuroendocrine differentiation arising in an ileal diverticulum: report of a case.

A 62-year-old man presented with right-sided abdominal pain. Radiologic examinations disclosed a solid tumor in the ileocecal mesentery that obstructed the right ureter, thus resulting in urinary extravasation. An en bloc tumor resection with the ascending colon, the terminal ileum, and a portion of the right ureter was performed. Histopathologically, the tumor was adenocarcinoma with extensive neuroendocrine differentiation which had arisen in an ileal diverticulum. The patient developed metastases to the lymph nodes, liver, and brain, and died 18 months after surgery.