Endometrioid adenocarcinoma of the colon arising from rare malignant transformation of extra-gonadal endometrioma

Background

Endometriosis is a common condition with a rare malignant potential. We report a case of a patient with a colon mass who underwent surgery for malignant endometriosis associated cancer.

Case: A 70-year-old woman with a pelvic mass who was lost to follow-up for 6 years represented with an enlarging pelvic mass involving the sigmoid colon. The patient underwent colonoscopy which revealed atypical endometrial-type glandular proliferation. She then underwent exploratory laparotomy with total abdominal hysterectomy, bilateral salpingo-oophorectomy, rectosigmoid resection, and creation of end colostomy. Final pathology revealed endometrioid adenocarcinoma arising from colon serosal endometriosis. Observation or systemic chemotherapy were considered, and patient opted for observation.

Conclusion

We report a case of malignant intestinal endometriosis. There is limited evidence to support a standardized approach to treatment due to the rare nature of this disease; the patient opted for observation. By understanding the presentation, diagnostic workup, and outcomes of each patient with malignant endometriosis, future research can be guided to ultimately improve patient outcomes.