Umbilical endometriosis in a woman with bicornuate uterus.

A 39-year-old woman presented for evaluation of a tender nodule on the umbilicus that had been present for 6 months. She stated that it had slowly been increasing in size and would occasionally open up and crust over with dried blood. Physical examination revealed a 4-mm firm, tender, brown papule in the umbilicus (Figure 1). She had a history of chronic pelvic pain and exploratory laparoscopy for endometriosis 10 years prior, at which time the diagnosis ofa bicornuate uterus was made. Subsequently, hysterectomy was performed (Figure 2) at which time the entire umbilical lesion was excised. Histopathology revealed branching tubular glands in the dermis lined by stratified columnar epithelium, surrounded by small cells with scant cytoplasm, characteristic of proliferative-phase endometrial stroma (Figure 3 and Figure 4). These findings were consistent with a diagnosis of umbilical endometriosis (Villar's nodule). Subsequent examination revealed no evidence of recurrence.