Sertoli-stromal cell tumor of the ovary: Immunohistochemical, ultrastructural, and genetic studies

The Sertoli-stromal cell tumor (SSCT) of the ovary shows a histologic resem blance to developing or adult testes and is often associated with virilizat ion caused by tumor-produced androgenic hormone. In spite of the unique man ifestation of SSCT, detailed characteristics of this tumor are still obscur e. The mechanism by which SSCT occurs has not yet been determined. Six SSCT s were studied immunohistochemically, ultrastructurally, and by polymerase chain reaction (PCR) for the presence of sex-determining region Y (SRY) gen e and the X chromosome activation state. Immunohistochemically, Sertoli-lik e cells of SSCT were positive not only for alpha -inhibin but also low-mole cular-weight cytokeratin. In control testes, the expression of a-inhibin an d cytokeratin was limited to a Sertoli cell component and rete testis, resp ectively. Ultrastructurally, tumor cells composing hollow tubules had an el ongated nucleus with deep indentation and annulate lamellae, which are char acteristic structures of mature Sertoli cells. In addition, they had studde d microvilli on the apical surface and frequent desmosomes, which are struc tures noted in the cells of rete testis. Histologically, tumor cells of hol low tubules sometimes pouted into the lumen, as did the cells of tubulae re te, entrance into rete testis froth seminiferous tubules. All of these find ings indicate that some tumor cells of a SSCT show simultaneous differentia tion into both Sertoli cells and cells of rete testis. SAY gene was not det ected in any cases, and the X chromosome activation pattern was the same as that of the female control. HUM PATHOL 32: 796-802. (C) 2001 by W.B. Saund ers Company.