Lateral buttock and postanal congenital dermal sinus tract.

We present 2 rare cases of lateral buttock and postanal congenital dermal sinus tract. These 2 children were noted to have a pit in the left upper lateral buttock and a postanal orifice after birth. Magnetic resonance imaging, computed tomography, and ultrasonography showed an inflammatory mass lesion in the buttock and a funicular structure adjacent to the rectum. Fistulography showed no connection between the pit and orifice. Surgical exploration revealed firm tracts from both the lateral buttock and postanus running deep to the tip of the coccyx. Histopathologic findings showed squamous cells in the walls of the sinus tracts. Our report broadens the clinical literature regarding congenital dermal sinus tract. We postulate that this disease may not always have a connection with the central nervous system, and our cases may provide examples of anal fistulas of congenital etiology in infants.