Cystadénocarcinome appendiculaire fistulisé à la peau

Background. - Cutaneous metastasis of colorectal cancer is rare. We report a case of fistular Lesions of the buttocks revealing a mixed tumour of the appendix involving mucinous cystadenocarcinoma and carcinoid tumour. Case report. - A 67-year-old woman was admitted for four skin fistulae of the right buttock present for 6 years. Histological examination of skin biopsy specimens identified infiltration of the dermis by metastatic mucinous adenocarcinoma while colonoscopy showed a caeca' tumour measuring 4 cm. Surgical excision was performed involving right hemicolectomy, evacuation of retroperitoneal mucin collection and excision of fistulae. Histopathological examination of surgical specimen confirmed mixed tumour consisting of perforated mucinous cystadenocarcinoma and carcinoid tumour of the appendix. Recurrence of the fistular lesions was seen. The patient was hospitalized several times for surgical drainage of mucin. She died one year later. Discussion. - Cutaneous metastasis of colorectal cancer is an uncommon event that usually occurs after identification of the primary tumour and generally indicates advanced-stage disease and an ominous prognosis. This case is particular and underlines the need to rule out a metastatic origin of cutaneous fistulae, even in patients otherwise apparently in good health. (C) 2010 Elsevier Masson SAS. All rights reserved.