Umbilical Nodule with Cyclical Bleeding: A Case Report and Literature Review of Atypical Endometriosis

Endometriosis is defined as the presence of endometrial glands and stroma outside the uterus. It affects 3 to 10 percent of women of reproductive age. Umbilical endometriosis is rare, with an estimated incidence of 0.5–1.0% among all cases of endometriosis, and is usually secondary to prior laparoscopic surgery involving the umbilicus. In this report, we described a case of umbilical endometriosis treated with surgical resection and highlight the great importance of medical history compared to complementary diagnostic tests that can be sometimes inconclusive.