Endometriosis of the Vermiform Appendix Presenting as Acute Appendicitis.

Endometriosis is characterized by the growth of endometrial tissue outside the uterine cavity. Endometriosis of the appendix is rare and its preoperative diagnosis is difficult. We report the case of a postmenopausal woman who presented with right lower quadrant abdominal pain concerning for acute appendicitis. Histopathological examination of her appendix revealed endometriosis and her abdominal pain resolved after appendectomy.