A Case of Multifocal Microcarcinoids and Rectal Adenocarcinoma in Long-Standing Ulcerative Colitis

Hisahiro Hosogi, Satoshi Nagayama, Junichiro Kawamura, Akinari Nomura, Atsushi Itami, Hiroshi Okabe, Suguru Hasegawa, Seiji Satoh, Go Watanabe and Yoshiharu Sakai

Department of Surgery, Graduate School of Medicine, Kyoto University

A 54-year-old man with a 30-year history of ulcerative colitis (UC) involving the entire colon underwent total surveillance colonoscopy, which showed the presence of a dysplasia-associated lesion or mass (DALM) in the rectum. Since the endoscopically resected DALM was found to be well-differentiated adenocarcinoma, the man underwent total laparoscopic proctocolectomy with an ileal pouch and anal anastomosis in 2006. Pathological examinations including chromogranin A staining of the resected specimen showed multifocal proliferation of endocrine cells in the crypts and multifocal microcarcinoids in the rectal mucosa. The literature contains 26 case reports of pathologically documented carcinoid tumors or microcarcinoids in colons of UC patients. These carcinoids are frequently found in total-colon UC (88%) and in long-term UC patients, whose average morbidity is 13.4 years. Of the 26 patients, 10 (38.5%) developed dysplasia or adenocarcinoma of the colon. It is well documented that long-term UC, especially total-colon UC, is complicated by the development of colorectal adenocarcinoma or dysplasia due to field injuries involving pluripotential stem cells of the colorectal lining induced by chronic mucosal inflammation. Although the incidence of carcinoid tumors or microcarcinoids arising in UC-affected colons is relatively low, microcarcinoids may develop due to reactive phenomena induced by persistent chronic mucosal inflammation, a mechanism similar to that seen in colitic cancer development.

Key words
microcarcinoid, colitic cancer, ulcerative colitis

Reprint requests
Satoshi Nagayama Department of Surgery, Graduate School of Medicine, Kyoto University
54 Kawaharacho, Shogoin, Sakyo-ku, Kyoto, 606-8507 JAPAN

Accepted
November 28, 2007

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