Leiomyoma of the Urinary Bladder

ABSTRACT

Leiomyoma is commonly found in the female genital tract, but occurrence in the urinary bladder is very rare with only 235 cases reported in the literature. These tumors have been classified as intravesical (63%), intramural (7%) and extravesical (30%) depending on the direction of the growth. We report a case of intravesical leiomyoma of the urinary bladder in a 36 year-old woman who exhibited dysuria and urinary retention. The gross and microscopical findings of leiomyoma of the bladder are similar to those of the uterus. Immunohistochemical stains for estrogen receptor (ER) and progesterone receptor (PR) revealed diffuse nuclear staining in smooth muscle cells, supporting the hypothesis of hormonal influence in tumorigenesis.