LAUSR

Dear Sir, Tumours of an end ileostomy are rare but have been documented in association with dysplasia, backwash ileitis and chronic irritation due to ileal secretion contaminating the surrounded skin. In some published cases the diagnosis was missed and changes were attributed to pyoderma gangrenosum or simply periostomal skin changes. We present a 65-year-old man diagnosed with ulcerative colitis who underwent a total colectomy with end ileostomy in 1970. In 2016 several skin lesions were observed and treated by the stomatherapist. After 1 month of treatment a biopsy was taken and the patient was diagnosed with a signet ring carcinoma of the end ileostomy. An ileoscopy and MRI and CT scans were performed and no other lesions or metastasis were identified. The patient underwent a resection of the tumour and relocation of the new ileostomy to the contralateral side. Pathological examination of the resected specimen confirmed a mucinous signet ring adenocarcinoma with myocutaneous extension but tumour-free resection margins (Video S1). Common complications of an end ileostomy include fistulas, stenoses, prolapses, parastomal abscess or retraction. The appearance of a neoplasm in an end ileostomy is exceedingly rare – an estimated incidence of two to four cases in every 1000 ileostomies [1–6]. Most tumours occur in well established, mature ileostomies, often of more than 15 years standing, although exceptions have been reported [5]. Chronic irritation with resulting metaplasia or backwash ileitis have been suggested as possible causative factors. The presence of peristomal changes, resistant to topical therapies, should alert one to the possibility of malignant change and a biopsy is recommended [4,6]. Many authors recommend an annual follow-up for patients with ileostomy with the aim of detecting such tumours. Treatment is complete tumour excision with free margins, if possible, and either ileostomy relocation or closure where possible [4,5].