Bilateral Brenner tumors: a case report and review of the literature.

Although the first Brenner tumor was reported in 1898 by MacNaughton-Jones, it was not until 1907 that Fritz Brenner described the tumor that bears his name. Since then more than 500 cases have been reported with bilaterality ranging from 3.7 to 8.0 per cent. However, this percentage is probably high. The tumor was originally thought to arise from follicular epithelium. Several other etiologies of the Brenner tumor have been suggested, including celomic surface epithelium, Walthard rests, teratoma, urothelium, and rete ovarii. The majority of Brenner tumors are inert, but there have been reports suggesting endocrine activity. The question of malignant transformation of the Brenner tumor has gained attention since Von Numers described the first malignant Brenner tumor in 1945. The determination of malignancy of these tumors has been hampered by vague histologic criteria for malignancy. The confusion surrounding the histogenesis, hormonal capabilities, and malignant potential of the Brenner tumor has persisted. A case report of bilateral Brenner tumors of the ovaries is presented as well as a review of the literature with emphasis on the bilaterality of Brenner tumors.