ENDOMETRIAL CARCINOMA IN-SITU IN POSTMENOPAUSAL WOMEN

In a review of 518 nonirradiated hysterectomy specimens with endometri al carcinoma and 39 with carcinosarcoma, 86 cases were identified in w hich there were microscopic foci of malignant epithelium that failed t o alter the architecture of an otherwise thin atrophic or weakly proli ferative endometrium or endometrial polyp. These changes were interpre ted to be endometrial carcinoma in situ (ECIS). This change was presen t on the surface (SCIS), in isolated glands (GCIS), and in small (thre e to five) groups of glands (thin AH). For these three subtypes, neith er papillations, stromal reaction, nor glandular epithelial bridging w ere present. When they were present and there was either no stromal re action or the reaction was limited to one or two glands in the absence of myometrial invasion or endometrial architectural alteration, they were designated as thin carcinoma (thin CA), a fourth subtype of ECIS. For these patients the age range was 50-90 years, with mean and media n ages of 66 and 65 years, respectively. All but one patient was known to be postmenopausal. In 66% of cases the endometrial malignancy eith er was uterine papillary serous/clear cell carcinoma (UPS) or containe d an element of UPS. Foci of ECIS were present adjacent to the tumor i n 86%, isolated from the tumor in 59%, and diffuse in 16% of cases. It is proposed that in many postmenopausal women, either surface epithel ium or individual glands undergo malignant transformation and then pro gress to an invasive malignancy without an intervening phase of atypic al hyperplasia, particularly in cases with an element of UPS.