Primary adenocarcinoma in peristomal skin: a case study.

Primary adenocarcinoma at an ileostomy site is an exceedingly rare occurrence but has been documented at the peristomal skin of patients with a long-standing ileostomy. Chronic irritation and resultant metaplasia is thought to be a key underlying mechanism for this phenomenon. Biopsy of newly developing lesions in the peristomal area of long-standing stomas is essential in order to avoid delayed diagnosis and limit complications. A 37-year-old man with a history of ulcerative colitis and ileostomy surgery 18 years prior presented with an asymptomatic polypoid lesion at the mucocutaneous junction. Initially diagnosed as pyogenic pranuloma, the lesion was treated using topical silver nitrate. This did not resolve the lesion but ulceration and bleeding were observed. A biopsy showed evidence of primary adenocarcinoma arising from the ileostomy site. The lesion was removed surgically, an ileo-anal J pouch was created, and the patient is currently receiving long-term follow-up and monitoring for any possible future complications. This case study is one of several in the literature suggesting that a high index of suspicion is warranted when ileostomy patients, especially those with a history of ulcerative colitis, present with unusual peristomal lesions.