Polypoidal rectal endometriosis—a diagnostic dilemma

Polypoidal rectal endometriosis is a rare and diagnostically challenging manifestation of deep infiltrating endometriosis that may mimic colorectal malignancy, especially in women lacking classical cyclical symptoms. We report such a case of 37-year-old female with a 2-year history of non-cyclical rectal bleeding, weight loss, and spontaneous passage of polypoid tissue per rectum. Imaging studies revealed findings suspicious for malignancy, while repeated endoscopic biopsies showed only inflammatory or hyperplastic colonic epithelium with reactive atypia. Histopathological examination of the resected specimen rendered the diagnosis of polypoidal rectal endometriosis. Immunohistochemistry demonstrated strong estrogen receptor positivity in both glandular and stromal components. This case highlights the need to consider endometriosis in reproductive-age women with unexplained rectal symptoms. Early multidisciplinary evaluation is key to accurate diagnosis and avoiding unnecessary interventions.