Deep rectal endometriosis mimicking colorectal cancer – Case report

Introduction: Deep infiltrating endometriosis(DIE) can be diagnosed if endometrial-like tissueinvades visceral organs deeper than 5 mm. DIE ismostly found in the rectum and can bemisdiagnosed with colorectal cancer.Case presentation: A 43-year-old woman came toour clinic with suspected colorectal cancer,complaining about alternating diarrhea andconstipation, tenesmus, and abdominal bloating.Colonoscopy and imaging test revealed around 3cm lesion, and histopathology of the biopsyrevealed low-grade dysplasia. Partial resection of the intestine with lesion was performed and thefinal diagnosis confirmed deep rectalendometriosis.Conclusion: Histopathological diagnosis can bedifficult because of the possible coexistence ofendometriosis and atypical glandular components inthe intestines. DIE should be taken intoconsideration as one of the probable diagnoses inpatients with a mass in the rectum.