Benign Mixed Mesodermal Tumors of the Uterus: A Histogenetic Study

Seven cases of benign mixed mesodermal tumors of the uterus were compared histologically with an equal number of randomly selected angiomyolipomas of the kidney. They were found to be indistinguishable in terms of the appearance and relative amounts of fat, smooth muscle, and fibrous connective tissue present. Furthermore, proliferation of atypical blood vessels, as has been found in the renal lesions, was a prominent feature in four of the seven uterine tumors. Based on the similarity of the histologic appearances, a common histogenesis is suggested.