Modern aspects of morphology of endometrial cancer and neuroendocrine tumors (to the 100th anniversary of the birth of O.K. Khmelnitsky)

November 4, 2020, marks the 100th anniversary of the birth of Oleg Konstantinovich Khmelnitskiy, an outstanding Russian pathologist, Corresponding Member of the Russian Academy of Medical Sciences (04.11.1920–08.02.2004). The creative legacy of O.K. Khmelnitskiy has a large number of works devoted to endometrial cancer and neuroendocrine tumors. Modern concepts of these tumors take a lot from the scientist’s ideas. The development of the classification of endometrioid carcinomas is determined by new data in molecular genetic research. The most common genetic changes in endometrioid adenocarcinomas involve mutations in the PTEN, KRAS, CTNNB1, PIK3CA, and MS1 genes. Serous carcinomas are characterized by TP53 mutations and HER2-neu gene amplification. The immunohistochemical panel allows differentiation of endometrioid and serous carcinomas. There is evidence of the role of the POLE gene mutation. Various advantages of the introduction of molecular genetic classification are presented, which allow changing approaches to the treatment of endometrial cancer depending on the risk of its development. The 2019 neuroendocrine tumors (NETs) classification allows interpreting morphological characteristics of these tumors in a new way.