287 A Rare Case of Appendiceal Endometriosis Mimicking Acute Appendicitis in a Middle-Aged Woman: A Case Report

Abstract Introduction/Objective Appendiceal endometriosis is an entity commonly affecting women of childbearing age, where endometrial tissue is abnormally found in the appendix. It often mimics acute appendicitis wth symptoms like right lower abdominal pain, nausea, and vomiting. A high index of suspicion is needed for clinicians to consider it a potential diagnosis, with a definitive diagnosis made after an appendectomy through histology. Methods/Case Report A middle-aged woman presents to the Emergency Department with complaints of right lower quadrant pain radiating around her back, associated with nausea and vomiting. Computed tomography (CT) scan of the abdomen and pelvis reveals a dilated appendix. A laparoscopic appendectomy was performed, and the specimen was submitted for histological evaluation. Results The specimen shows an intact appendix with mesoappendix measuring 3 cm in length and 1 cm in average diameter. The serosal surface is gray and smooth. Cross-sections reveal no mass/nodule, and the specimen was entirely submitted. Microscopic examination shows diffuse areas of endometrial glands and stroma within the muscularis propria and serosa layer of the appendix wall without acute inflammatory changes. An assessment of appendiceal endometriosis was made for this case. Conclusion Appendiceal endometriosis, often mistaken for acute appendicitis, poses diagnostic challenges, especially in women of childbearing age, due to its nonspecific symptoms and reliance on microscopic examination. This case highlights the need for a high index of clinical suspicion and awareness for accurate diagnosis and improved patient care.