Synchronous Appearance of a High-Grade Neuroendocrine Carcinoma of the Ampulla Vater and Sigmoid Colon Adenocarcinoma

Neuroendocrine carcinoma is a relatively rare tumor and its coexistence with other primary cancers is very exceptional. We present a case of a 63-year-old woman with biliary obstruction due to a high-grade neuroendocrine carcinoma located in ampulla of Vater who was found to have a synchronous sigmoid colon adenocarcinoma while undergoing staging laparotomy and pancreas head resection. Medical history was significant only for basal cell skin cancer. Immunohistochemical examination revealed the concurrence of histologically proved neuroendocrine carcinoma (chromogranin A, synaptophysin, and CD56 were positive) and Stage II (T3, N0, and M0) according to the TNM staging classification of colorectal cancer. The coexistence of neuroendocrine tumors with either synchronous or metachronous unrelated cancer is increasingly recognized. The patients with neuroendocrine carcinoma should be evaluated for secondary primary malignancies.