A leiomyomatous uterus contains leiomyomas, or benign growths, on its muscular wall. Leiomyomas are also called myomas, fibroids and fibromyomas because they contain fibrous tissue. They are the most common type of pelvic tumor.
Leiomyomas are common among women in their 40s and 50s and are the main cause of hysterectomies for about 25 percent of women in this age group. Twenty-five percent of white women and 50 percent of black women develop leiomyomatous uteri. Although only a quarter of women with a leiomyomatous uterus require hysterectomies, 77 percent of all women who have hysterectomies show the tumors in the pathology results.