Case report

Synchronous mucinous adenocarcinoma of the rectosigmoid seeding onto a pre-existing anal fistula

Nemandra Sandiford¹ , Patsy R Prussia² , Antonio Chiappa³ and Andrew P Zbar¹

¹  Professorial Department of Surgery, School of Medicine and Clinical Research, Queen Elizabeth Hospital, Barbados

²  Department of Pathology Queen Elizabeth Hospital, Barbados

³  Department of Surgery, European Institute of Oncology and University of Milano –, Italy

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International Seminars in Surgical Oncology 2006, 3:25doi:10.1186/1477-7800-3-25

Published:	8 September 2006

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.