Endometrioid adenocarcinoma arising from colon endometriosis

Endometriosis-associated intestinal tumors represent the malignant transformation of gastrointestinal endometriosis. Approximately 50 cases have been reported in the literature. They are most commonly found among women aged 30–60 years, whereas exogenous hormone therapy and obesity are primary risk factors for the malignant transformation of endometriotic lesions. Clinical features simulate a primary colonic carcinoma. A high index of suspicion in conjunction with careful histological and immunohistochemical examination (CK7, CK20, CDX2, CD10, ER, and PR) is important for establishing a correct diagnosis. In this article, a rare case of a postmenopausal woman with no risk factors and conflicting clinical presentation, diagnosed with endometriosis-associated intestinal tumor, is described.