title: Synchronous mucinous adenocarcinoma of the rectosigmoid seeding onto a pre-existing anal fistula.
abstract: Carcinoma within a long-standing fistula-in-ano is rare and may be defined by specific neoplastic involvement of the fistulous track in the absence of rectal mucosal carcinoma. The presence of a carcinoma of mucinous histology occurring synchronously in the perianal region and the colon is exceptionally rare. We present a case with a review of the literature concerning its aetiopathogenesis and treatment. A 72-year-old man with a 2 months history of dark red rectal bleeding and mucus per rectum with alternating constipation and diarrhoea, was observed. Clinical examination and a barium enema showed a perianal fistula and an annular stenosing lesion of the rectosigmoid. Preoperative CT scan confirmed the colonic lesion. Colonic resection and wide fistula excision were performed. Histology showed an adenocarcinoma with a clear resection margins. The fistula also showed a similar histology. Chemoradiation (5-Fluorouracil (425 mg/m2) and Leucovorin (20 mg/m2) with 4500 cGy external beam radiotherapy was utilized. Subsequent clinical follow-up and CT examination of the patient has not revealed recurrent disease at 14 months.
authors.affiliation: Department of Surgery, School of Medicine and Clinical Research, Queen Elizabeth Hospital, Barbados.
authors.forename: Nemandra
authors.initials: N
authors.lastname: Sandiford
authors.forename: Patsy R
authors.initials: PR
authors.lastname: Prussia
authors.forename: Antonio
authors.initials: A
authors.lastname: Chiappa
authors.forename: Andrew P
authors.initials: AP
authors.lastname: Zbar