[Pathological analysis and etiological study on uterine leiomyoma]

The morphologic observations of uterine leiomyoma in 100 cases and the histogenetic study on the uterine muscles of three-month to full-term fetuses in 14 cases have been made. It is found that there exists a transitional feature of perithelial cells, which probably are the cellular anlagen of hysteromyoma and uterine smooth muscle of fetus. Those cells are similar to the fifth month fetal uterine wall cells and might belong to the rudimentary mullerian tissue. Histologically, the hysteromyoma could be divided into five cellular types: mature cell type, proliferative cell type, blastocyte type, retrogressional cell type and mixed cell type. The blastocyte type might be related to an elevated level of estrogen and 59% of retrogressional cell type occurs in the patients above 50 years old.