Large epidermal inclusion cyst presenting as a pelvic mass.

INTRODUCTION Epidermal inclusion cysts are common discrete nodules often formed in areas of previous trauma or surgery. A literature review indicated that large epidermal inclusion cysts of the pelvis are extremely rare. Accordingly, we present a case of a woman with a large pelvic epidermal inclusion cyst of the vaginal cuff, along with imaging studies and a review of the literature. CASE PRESENTATION A 49-year-old woman, 13 years after vaginal hysterectomy, was found to have a 7-cm soft tissue pelvic mass, discovered on a computed tomography (CT) scan performed for abdominal pain. The transvaginal ultrasound showed typical findings of an unruptured epidermal inclusion cyst with a hypoechoic background with diffuse small variable echodensities (some intense echogenic reflectors), a thin wall, and no internal Doppler flow. A 7-cm epidermal inclusion cyst was removed laparoscopically from her vaginal cuff without complication. DISCUSSION Epidermal inclusion cysts of clinical significance are rarely formed at the vaginal cuff or elsewhere in the pelvis. Increased utilization of abdominal/pelvic CT imaging is increasing the frequency in which benign pelvic cysts are encountered. The trauma of surgery may sequester portions of vaginal epithelium, which may form epidermal inclusion cysts. As the cyst increases in size, the cyst may be viewed as an incidental pelvic mass requiring clinical decision making.