Hysteroscopic and Immunohistochemical Findings in Type I and Type II Endometrial Carcinomas

To determine whether types I and II endometrial carcinomas have different precursor lesions recognized at hysteroscopy and immunohistochemistry. Single center case study (Canadian Task Force classification II-2). A private, university affiliated hospital. One hundred forty-six postmenopausal women with endometrial pathology diagnosed by hysteroscopy and biopsy. Hysteroscopy and imunohistochemical determination of p53 overexpression. The number of cells showing p53 overexpression was low in endometrial polyps, hyperplasia, and G1 endometrioid carcinomas. A marked increase was seen only in high-grade G2–G3 endometrioid carcinomas and in cases of uterine papillary serous carcinoma. In the latter, strong p53 overexpression was detected in early forms still confined to endometrial polyps. Hysteroscopy could not differentiate between high- and low-grade endometrioid carcinomas. The p53-driven pathway plays an important role in the origin of papillary serous carcinoma but not in G1 endometrioid cancer that evolves from estrogen-stimulated endometrium. However, this pathway is important for progression of low-grade endometrioid carcinomas to higher-grade tumors.