Recent developments and selected diagnostic problems in carcinomas of the endometrium.

Two major types of endometrial carcinoma have been well described as differing not only in their pathogenesis but also in their behavior, therefore requiring different management. These implications make the differential diagnosis between the 2 pathogenetic types, specifically their prototypes, endometrioid and serous endometrial carcinomas, paramount. However, this differential diagnosis may be difficult owing to overlapping histologic features such as papillary architecture. To that end, the differential diagnosis of endometrial tumors with papillary morphologic features is discussed in detail. Preinvasive and early invasive serous carcinoma (endometrial intraepithelial carcinoma and minimal serous carcinoma) have been claimed to have a good prognosis if accurate staging confirmed lack of extrauterine spread. Definitions and diagnostic features of these small serous lesions are described. In addition, several recently described variants and histologic patterns of endometrial carcinoma that might present diagnostic problems, such as microglandular mucinous carcinoma, sertoliform carcinoma, carcinoma arising in an atypical polypoid adenomyoma, and endometrial carcinoma with a minimal deviation adenocarcinoma pattern of myoinvasion, are described.