Isolated Appendiceal Endometriosis

Pain associated with appendiceal endometriosis can mimic other intra-abdominal pathology. The diagnosis is usually obvious during gross inspection of the appendix; however, the absence of classical macroscopic appearances may lead to missed cases in which the patient's pain is misdiagnosed and inappropriately managed.

A 34-year-old woman presented with cyclical right iliac fossa pain and an elevated serum C-reactive protein of 13 mg/L (normal < 5 mg/L). Diagnostic laparoscopy showed an isolated appendiceal mass with no pelvic endometriosis, and an appendectomy was performed. Histopathology demonstrated appendiceal endometriosis without macroscopic involvement of other pelvic organs.

This case gives insight into the pathophysiology of endometriosis. We advocate routine appendectomy in women with unexplained recurrent abdominal pain because a diagnostic laparoscopy may miss isolated endometriosis of the appendix, and we now have evidence that this may have no external features suggesting the diagnosis. Additionally, endometriosis can involve the gastrointestinal tract without involvement of the reproductive organs. This is important information in the further progression of theories underlying the pathophysiology of endometriosis.