Adenocarcinoma of a Brooke ileostomy for adenomatous polyposis coli

A case of primary adenocarcinoma of a Brooke ileostomy after proctocolectomy for adenomatous polyposis coli is reported, and three additional cases collected from the literature are described. This rare tumor is seen at an average interval of 22 yr after colectomy with ileostomy. In all four cases, the mucosa adjacent to tumor had straight tubular glands lined by goblet cells and an absence of villi characteristic of colonic mucosa. Mucosal biopsies in all four stained positive for colonic sulfomucin. The clinical and morphologic features indicate a progression from ileal mucosa to colonic mucosa, colonic dysplasia, and finally, adenocarcinoma. Thirteen patients with adenocarcinoma of the ileostomy after proctocolectomy for ulcerative colitis have also been reported. Annual ileostomy examination, biopsy of suspicious lesions, and wide excision of carcinoma with stomal revision are recommended.