A study of a large cell calcifying
Sertoli cell tumor of the testis associated with bilateral
gynecomastia in an 8-year-old boy is presented. Macroscopically, the two testes showed multiple, large, and hard calcified nodules. Histology revealed clusters or cords of
tumor cells with foci of calcifications as well as evidences, in the adjacent testicular parenchyma, of initiation of gonadal development, such as early signs of spermatogenesis and sparse Leydig cell differentiation. In vivo, serum
hormone studies showed
gonadotropin-independent gonadal activity. After
orchidectomy two macroscopically distinct fractions of the removed testes, tumoral and extratumoral, were processed separately for cell isolation and culture. The secretion of
testosterone,
androstenedione, and
17-hydroxyprogesterone to the medium on day 6 of culture showed that steroidogenesis in cells of the extratumoral fraction was more active than in the tumoral fraction. On the other hand, tumoral fraction cells showed much higher
aromatase activity than extratumoral cells. Furthermore,
conditioned medium of tumoral fraction cells was able to stimulate
testosterone secretion when it was added to subcultures of testicular cells isolated from a control subject. It is postulated that tumoral cells might have stimulated neighboring interstitial cells to differentiate into Leydig cells and to secrete
androgens, which in turn might have been aromatized to
estrogens by tumoral cells.