[Cytogenetic study of endometrial carcinoma]

Cytogenetic studies were performed on endometrial specimens of four patients with hyperplasia. Six with adenocarcinoma and one with mixed mesodermal tumor. All 65 cells obtained from hyperplasia specimens excluding one cell, had a normal female karyotype. However, cells from five adenocarcinoma specimens had chromosomal abnormalities, though a specimen of a well differentiated adenocarcinoma showed a normal karyotype. A few numerical abnormalities which were clonal in origin, were noted in one case each. Three kinds of structural abnormalities involving chromosomes 1 were identified as clonal in origin; del (1) (p21), t. dic(1; 16) (p21; q24), and i (lq). Since carcinoma cells had two chromosomes 1 of normal morphology, the presence of the marker chromosome led to the partial trisomy or tetrasomy of the long arm of a chromosome 1, being characteristic of cells from adenocarcinoma of the endometrium. A successively transplantable tumor has been produced from a poorly differentiated carcinoma cells with the t. dic (1; 16) (p21; q24) marker chromosome. Histological and chromosomal examinations were performed in cells from the passage 1, 4 and 5 tumors in order to explore the role of this marker played in the formation of the endometrial carcinoma. Though the degree of differentiation status of tumor cells had been changed during transplantations, the t. dic (1; 16) (p21; q24) marker were observed consistently among these cells. This suggested that the rearrangement of chromosome 1 was not produced as a result of genetic instability due to tumor progression, but rather specifically associated with the endometrial carcinogenesis. None of karyotypic changes excluding the marker and the tetraploid was responsible for these phenotypic changes.