[Sex chromatin in oncomorphology].

SCr body is a label of repression of one of the sex chromosomes (X chromosome in women or Y chromosome in men) in the interphase nucleus. By the end of the synthesis period these chromosomes undergo derepression since DNA replication occurs. Thus, by the end of the synthetic and in premitotic periods of the cellular cycle the SCr body disappears. In tumors of various locations, a clear-cut inverse proportional dependence between a decrease in the number of nuclei with SCr bodies and an increase in the mitotic index was demonstrated. Therefore, the CSr test is an index of the growth rate (proliferative activity) of the examined tumor. By this test it is possible to determine the degree of the tumor progression, to assess the mitotic activity in small pieces of biopsy materials. The SCr test may be an additional method for differential diagnosis of malignant tumors.