Appendicitis with Appendicular Phlegmon Secondary to Endometriosis

Acute appendicitis is a common surgical emergency, however endometriosis in an appendix is a rare phenomenon. In this case report, we describe a 34-year-old woman who visited a teaching hospital on 2024, presenting with typical clinical features of appendicitis. Initial imaging revealed complicated appendicitis with perforation and an appendicolith; following conservative management, the patient was scheduled for an interval appendectomy which revealed an appendicular mass. A repeat surgery was scheduled, where extensive adhesions were noted, resulting in an open appendectomy. Histopathological examination confirmed appendiceal Endometriosis and a follow-up by a gynaecologist was arranged. Appendiceal Endometriosis is a rare phenomenon with variable clinical presentations, a high index of suspicion is necessary for women of childbearing age due to the risk of complications. The diagnosis of appendiceal Endometriosis is only confirmed via histopathology, and obtaining a Magnetic Resonance Imaging might aid in diagnosis; however, prompt surgical intervention is the standard of care.