Primary umbilical endometriosis (PUE).

Primary endometriosis of the umbilicus, Villars nodule, rarely occurs. It is characterized by a discolored change in the umbilicus which manifests itself with cyclic menstrual-related symptoms such as pain, swelling and bleeding. Often the diagnosis is based on objective findings, but imaging and histology predicts and verify the diagnosis. Radical excision is performed with good results. We present ten cases with primary umbilical endometriosis and present the referral pattern dominated by primary referral to the gastro-surgeon reflecting difficulties in finding the right diagnosis.