TESTICULAR-STEROID BIOSYNTHESIS IN A BOY WITH A LARGE-CELL CALCIFYINGSERTOLI-CELL TUMOR PRODUCING PREPUBERTAL GYNECOMASTIA

A study of a large cell calcifying Sertoli cell tumor of the testis as sociated with bilateral gynecomastia in an 8-year-old boy is presented . Macroscopically, the two testes showed multiple, large, and hard cal cified nodules. Histology revealed clusters or cords of tumor cells wi th foci of calcifications as well as evidences, in the adjacent testic ular parenchyma, of initiation of gonadal development, such as early s igns of spermatogenesis and sparse Leydig cell differentiation. In viv o, serum hormone studies showed gonadotropin-independent gonadal activ ity. After orchidectomy two macroscopically distinct fractions of the removed testes, tumoral and extratumoral, were processed separately fo r cell isolation and culture. The secretion of testosterone, androsten edione, and 17-hydroxyprogesterone to the medium on day 6 of culture s howed that steroidogenesis in cells of the extratumoral fraction was m ore active than in the tumoral fraction. On the other hand, tumoral fr action cells showed much higher aromatase activity than extratumoral c ells. Furthermore, conditioned medium of tumoral fraction cells was ab le to stimulate testosterone secretion when it was added to subculture s of testicular cells isolated from a control subject. It is postulate d that tumoral cells might have stimulated neighboring interstitial ce lls to differentiate into Leydig cells and to secrete androgens, which in turn might have been aromatized to estrogens by tumoral cells.