Endometriosis-associated intestinal tumors (EAITs) are rare malignancies that arise from ectopic endometrial tissue, and their clinical and molecular characteristics remain poorly defined.
A woman in her seventies presented with mucous hematochezia. Colonoscopy revealed a poorly differentiated adenocarcinoma in the upper rectum. Immunohistochemical staining showed CK7 positivity and CK20/CDX2 negativity, findings atypical for …