Preliminary Ultrastructural Evaluation of Uterine Leiomyomata

Leiomyomata are benign uterine tumors composed of smooth muscle cells and varying amounts of connective tissue. The tumor occurs in approximately 10% of all women with a greater frequency in Negro women. The reasons for growth and development of these tumors are yet unknown. Meyer and DeSnoo suggest that the tumors originate in cell rests or genitoblasts and, under estrogen stimulation, multiply to form the tumor. Witherspoon suggests an ovary-leiomyoma relationship, in which prolonged high estrogen levels are due to cystic change in the ovary secondary to pelvic inflammatory disease. Others have demonstrated development of leiomyomata in animal studies. Anderson proposes that development of the tumor stems from an undetermined connective tissue cell of either the myometrium or its blood vessels.