A 42-year-old woman presented with a 4-month history of erythematous umbilical nodule (Fig. 1A). She reported changes in the size and color of the lesion associated with occasional umbilical bleeding. Histopathologic examination demonstrated glands and endometrial stroma within the dermis (Fig. 1B), with immunohistochemical expression of estrogen receptors (Fig. 1C) and CD10. Subsequently, the patient confirmed that the umbilical bleeding coincided with menses. She denied dysmenorrhea or chronic pelvic pain and reported no history of previous surgery. The patient was referred to Gynecology, and diagnostic evaluation revealed no gynecologic involvement or ectopic endometrial foci.
Umbilical endometriosis is defined as the presence of endometrial glands and/or stroma within the umbilicus. Primary umbilical endometriosis occurs in the absence of a history of surgery. Typically, umbilical endometriosis presents as a red, purple, or black umbilical nodule associated with pain, catamenial symptoms, or bleeding. The gold standard treatment is surgical excision, with a postoperative recurrence rate of 4.7%.
