Gonadoblastoma: histologic, ultrastructural, and histochemical observations in five cases

In this series of gonadoblastomas it appeared that the germ cells were the motivating force underlying either tumor proliferation or regression. The ultrastructural morphology confirmed the presence of undifferentiated gonadal cells with active steroid synthesis by the interstitial cells. The Call-Exner-like bodies which showed extensive calcification were composed of basement membrane material containing a sulfated mucosubstance. A histochemical comparison with the noncalcifying Call-Exner bodies of a granulosa-cell tumor differed only in their glycoprotein content. The calcium deposits were identified as oriented hydroxyapatite crystals by electron diffraction, and it is proposed that the basement membrane material serves as a nucleation site for calcification. High serum testosterone levels were correlated with the presence solely of interstitial cells in one case. The finding of a gonadoblastoma without the presence of a Y chromosome contradicts earlier proposals concerning the requirement of a Y chromosome for germ cell proliferation.