Primary umbilical endometriosis revealed by tender and hemorrhagic umbilical swelling during menstruation.

Endometriosis is a relatively uncommon benign pathology that accounts for 0.5%-1% of all extra-pelvic endometriosis. This pathology is characterized by the presence of ectopic endometrial tissue outside the endometrial cavity and is accompanied by the clinical appearance of a bleeding umbilical nodule. Despite the non-specificity of the characteristic imaging signs, abdominal ultrasound and magnetic resonance imaging aid in diagnosis. We describe a case of primary umbilical endometriosis, as well as the clinical aspects and role of imaging in the positive diagnosis of this uncommon pathology.