A rare case of appendicular endometriosis mimicking appendicitis: a case report

Abstract Introduction Appendicular endometriosis is a rare condition accounting for 1%–3% of all intestinal endometriosis. The presentation of appendicular endometriosis is often nonspecific and may mimic appendicitis. Case Description A 23-year-old female presented with colicky lower abdominal pain, dysuria, and menstrual cyclic pain. Clinical examination and imaging, including ultrasound and CT scan, were inconclusive. Due to persistent symptoms and to exclude a focal appendiceal lesion, a laparoscopic appendectomy was performed. Intraoperative findings revealed a firm, dilated appendicular tip without signs of inflammation. Histopathological analysis confirmed appendicular endometriosis with endometrial glands, characterized by the presence of both endometrial glands and stroma, with immunoreactivity for CD10 in the stromal cells. The patient recovered postoperatively, and the pain has resolved. Discussion Appendicular endometriosis is diagnostically challenging. While laparoscopy is a primary tool for visualizing pelvic and appendiceal abnormalities, definitive diagnosis rests on detailed histopathological confirmation. This case highlights the diagnostic process of appendicular endometriosis and recommends including it as part of the differential diagnosis of acute lower abdominal pain. Learning points