A benign, borderline, or malignant epithelial tumor of the fallopian tube that is characterized by the presence of glands and/or cysts lined by neoplastic cells that resemble endometrial cells. The disease is fallopian tube endometrioid tumor (MONDO_0021576). Also known as: endometrium neoplasm of fallopian tube, fallopian tube endometrioid neoplasm, fallopian tube endometrium neoplasm.