Sex-Cord Tumors of the Testis

Abstract

Abstract: Sex cord tumors of the testis come in three pure forms— Sertoli cell tumors, Leydig cell tumors, and granulosa cell tumors— and pose many problems in differential diagnosis. Sertoli cell tumors are divided into those that are not otherwise specified, those with abundant stromal sclerosis, and the large cell calcifying variant. Most of the not otherwise specified tumors are associated with exquisite hollow or solid tubular patterns, but diffuse patterns may be present either focally or, in occasional cases, extensively. When prominent and associated with septa and inflammatory cells a superficial resemblance to seminoma may result, but careful attention to differentiating cytologic features of these two neoplasms should result in the correct diagnosis being made. If indicated, immunohistochemical stains will help resolve the issue. The large cell calcifying Sertoli cell tumor is more frequently bilateral than other sex cord tumors and is sometimes associated with a variety of unusual clinical manifestations. Rare peculiar proliferations of Sertoli cells in young boys with Peutz-Jeghers syndrome have recently been described, but their full clinical and pathologic spectrum remains to be elucidated. Leydig cell tumors represent the commonest of the pure sex cord tumors of the testis and usually are a straightforward microscopic diagnosis being characterized by diffuse or nodular growths of bland cells with copious eosinophilic cytoplasm. However, a variety of unusual patterns may be encountered including a spindle cell pattern, microcystic change and, in some cases, striking adipose metaplasia. Careful search for typical foci of Leydig cell tumor is crucial in establishing the correct diagnosis when these unusual patterns predominate. Granulosa cell tumors are subdivided into the juvenile adult forms as in the ovary. The juvenile form has a remarkable tendency to occur in most instances in the first six months of life. Although a solid and follicular growth pattern is usually diagnostic, occasionally irregular arrangements of neoplastic granulosa cells in a loose matrix may impart a superficial resemblance to another important testicular tumor of children, the yolk sac tumor. If indicated, immunohistochemical studies will distinguish between these two neoplasms, but routine light microscopy should suffice. The rarest pure sex cord tumor of the testis is the adult granulosa cell tumor. Its morphologic features are as seen in the ovary, although based on personal experience, Call-Exner bodies may be less frequent in the male. When lutein cells are present within these neoplasms it may lead to confusion with an unclassified mixed germ cell sex cord-stromal tumor. A number of granulosa cell tumors of the testis have been clinically malignant in contrast to the benign behavior, to date, of the testicular juvenile granulosa cell tumor.