[Umbilical endometriosis]

Endometriosis usually presents in the pelvic region, but extragenital endometriosis may occur in almost every other organ. Umbilical endometriosis represents 0.5-1.2 % of all cases of endometriosis, and can further be divided into primary and secondary presentation, occurring in women without and with umbilical scars, respectively. Common clinical presentation is periodic pain, swelling and bleeding.

A woman in her thirties without abdominal scars presented with a painful umbilical nodule with spontaneous periodic bleeding and swelling. MRI and fine needle aspiration cytology suggested umbilical endometriosis, and this diagnosis was confirmed histologically after surgical excision.

Umbilical endometriosis should be considered in cases of umbilical nodules with cyclic variation of symptoms. It is treated with simple surgical excision, and histopathology confirms the diagnosis. Approximately 20 % of patients also present with pelvic endometriosis, but diagnostic laparoscopy is only recommended if symptoms of pelvic endometriosis are also present.