[Endometrial carcinoma in situ. Morphological and immunohistochemical aspects]

A possible precursor for invasive endometrial carcinoma is an in situ stage, but this notion is very much debated. We present a case of endometrial carcinoma diagnosed in a patient with post-menopausal bleeding. The morphological examination of the hysterectomy specimen, processed by routine technique, put in evidence focal atypias of the glandular epithelium in a group of few endometrial glands, on a background of atrophy without a desmoplastic stromal reaction. The immunohistochemical investigation of the steroid receptors and p53 protein, using monoclonal antibodies in the ABC technique, revealed the p53 positivity and the absence of the receptors in the focal malignant areas. The surface epithelium had the same immunohistochemical aspect. These aspects were decisive in precising that the malignant change was primarily in the surface epithelium with secondary extension in some glands, the final diagnosis being in situ serous papillary carcinoma.