A retrorectal epidermoid cyst as the cause of recurrent anal fistula – a case report

Abstract

Inflammation of the anal crypt is the most common cause of anal fistula. Other causesof anal fistula include Crohn’s disease, injury (including iatrogenic), a foreign bodyand casuistic causes, such as tuberculosis, actinomycosis, etc. We present a case ofa patient receiving unsuccessful conservative and surgical treatment due to recurrent anal fistula caused by a congenital retrorectal epidermoid cyst. Extracutaneousepidermoid cyst is a rare pathology and a congenital defect. It develops between 4 and8 weeks’ gestation due to impaired ectodermal development. A complete resectionof the lesion following an accurate imaging diagnosis (transrectal ultrasonography or magnetic resonance) is the treatment of choice in symptomatic retrorectal epidermoid cyst. In the presented case, the patient underwent, following a diagnostic process, a surgery involving a complete resection of the fistula tract along with a groupof small cysts. During the surgery, no connection was found between the lesions andthe anus or the anal sphincters. The postoperative site extending above the analsphincters was allowed to heal by secondary intention. The patient was dischargedhome on day 3 post surgery. The wound healed after 12 weeks.Conclusions. Aetiology other than the anal crypt should be considered and an accurate preoperative diagnosis aimed to determine the cause of fistula and chooseappropriate therapeutic management should be established in the case of recurrentanal fistula and atypical course of disease.