The purpose of this paper is to reemphasize that pilonidal cyst infection may result in sinuses which reach the perianal region and simulate anal fistula. Five such cases are presented for addition to the literature. Although this condition occurs infrequently, individual cases have been reported in the recent literature * in sufficient number to warrant their consideration in the differential diagnosis of anal fistula.
Frequently when the secondary opening of an anal fistula is correctly located, the primary opening is either partially or completely sealed. The most valuable clinical observation in establishing the presence of an anal fistula is palpation of the tract leading from the secondary opening to the anus. This is present in the majority of cases. When no primary opening is observed and no tract palpable, the possibility of an extra-anal source of the infection must be considered.
The coexistence of anal fistula and pilonidal disease has been