Squamous cell carcinoma of the rectal stump in a patient with ulcerative colitis
Seid Hossien Mir-Madjlessi, M.D., F.A.C.P.
Richard G. Farmer, M.D., F.A.C.P.
A 52-year-old man presented with squamous cell carcinoma of the rectal stump. Severe ulcerative colitis had developed 10 years before diagnosis and he had had to undergo subtotal colectomy and ileostomy. This tumor is a rare complication of ulcerative colitis representing 1% to 2% of all cancers complicating ulcerative colitis, a relative incidence 50 to 100 times than in the general population. It is predominantly located at the rectum, but may involve other areas of the colon. As in adenocarcinoma, squamous cell carcinoma of the large bowel is seen almost exclusively in early onset, extensive or total colitis of nine years or more duration. If treated early, long-term survival is possible. In some patients, a second primary tumor may develop either in the colon or elsewhere. It is suggested that the development of squamous cell carcinoma of the large bowel requires chronic irritation of the colonic mucosa in patients with some predisposing genetic background or disturbed immune system. The literature on squamous cell carcinoma of the large bowel associated with ulcerative colitis is reviewed.