Primary umbilical endometriosis: case report and literature review of an unusual cause of catamenial umbilical pain

Endometriosis is defined by the presence of functional ectopic endometrial tissue outside the uterine cavity, excluding the myometrium. It is a benign tumor that can infiltrate and cling to other organs, mimicking a malignant tumor. Umbilical endometriosis is a rare type of endometriosis that can occur naturally or as a result of a surgical operation. We report the case of a patient who experienced catamenial umbilical discomfort and whose radiological examination revealed endometriotic involvement.