Bi-lobed Perirectal Epidermoid Cyst: An Unusual Cause of Hematochezia in a Middle-aged Woman

Perirectal epidermoid cysts are congenital cysts originating from the ectodermal germ cell layer of the hind gut. Their presenting symptoms are most often nonspecific and distinguishing them from other presacral developmental cysts often present a diagnostic and therapeutic dilemma. We present a 58-year-old woman who presented with chronic dyschezia and hematochezia of a few days duration and no prior colonoscopies. Initial blood work and tumor markers were unremarkable. Pelvic magnetic resonance imaging (MRI) showed a 7.5 cm × 5 cm × 6 cm homogenous bi-lobed cystic mass in the pelvis adherent to the left lateral wall of the rectum and posteriorly to the sacrum with a displacement of the rectum anteriorly and to the right. There was no pelvic sidewall adenopathy or free fluid in the pelvis. Preoperative colonoscopy showed rectal compression with no rectal involvement of the mass. The cyst was successfully resected posteriorly via the trans-sacrococcygeal approach. An intraoperative proctosigmoidoscopy confirmed an intact rectum. The patient remains recurrence-free 1 year postsurgical resection.