Endometriosis Presenting as a Malignant Appearing Cecal Mass

Endometriosis is a gynecological condition that can manifest in pelvic and extra-pelvic sites, including the gastrointestinal tract. Cecal and appendiceal involvement is rare and can present as anemia, mimicking malignancy. The discussed case is of a 50-year-old female who presented with symptomatic anemia. Imaging revealed a cecal and appendiceal mass with lymphadenopathy, raising concern for malignancy. Colonoscopy showed a suspicious tumor, but biopsy was inconclusive. Surgical resection revealed extensive endometriosis involving the cecum and appendix. Pathology confirmed endometriosis mimicking neoplasia. Postoperatively, the patient's anemia improved. This case highlights that gastrointestinal endometriosis is often asymptomatic and difficult to diagnose. Its presentation as a colonic mass underscores the need for broad differentials. Surgical intervention is crucial when malignancy is suspected.