Crohn's disease and colorectal carcinoma: rectal cancer complicating longstanding active perianal disease

Reports of Crohn's disease (CD)-associated colorectal carcinoma are being cited in the medical literature with increasing frequency. Our aim was to identify subgroups of patients with risk factors that may account for this.

We reviewed the medical records of 16 patients with the simultaneous diagnosis of CD and colorectal carcinoma and, in addition, reviewed previously reported cases of CD-associated colorectal carcinoma.

Eight male and eight female patients presented with 18 carcinomas: four right colon, four transverse, two descending colon, and eight rectal lesions. Median age at presentation was 48 yr. The mean duration of CD before presentation of carcinoma was 19.7 yr. Two lesions were discovered in strictured bowel segments. Two patients had multiple cancers. One had simultaneous cecal and left colon adenocarcinomas. The other underwent resection of a right colon lesion and 5 yr later presented with transverse colon carcinoma. Eight patients had rectal cancer; all were diagnosed preoperatively. Six of these patients had a history of severe perianal CD. Six had undergone multiple incision and drainage procedures for perirectal abscesses and fistulas. Two developed malignancies in defunctionalized rectal stumps. One of these patients presented with simultaneous squamous rectal carcinoma and papillary bile duct cholangiocarcinoma.

Gastrointestinal malignancy in association with CD has been reported. Symptoms of chronic inflammatory disease may obscure clinical manifestations of occult malignancy and thereby delay diagnosis. Crohn's patients with long-standing anorectal or perianal disease and stricture may well warrant surveillance endoscopy and biopsy of involved areas with the hope of earlier detection and treatment of these rectal cancers.