The fertile eunuch syndrome. An isolated leydig-cell failure?

In two patients exhibiting eunuchoid features in association with normal sized testes and complete spermatogenesis concommittant with only occasional Leydig cells between the tubuli, (proven by testicular biopsy) an attempt was made to elucidate the factors leading to this condition. Both patients responded with significant rise in both plasma FSH and LH after administration of synthetic GnRH indicating pituitary responsiveness. However, no rise in either FSH or LH could be observed after administration of clomiphene citrate during three weeks of treatment indicating hypothalamic unresponsiveness to chemical stimuli. Although plasma testosterone levels rose significantly after administration of Human Chorionic Gonadotropin, estradiol remained unchanged during three weeks of HCG administration. A hypothesis is discussed which defines this syndrome in these two cases as primary Leydig cells failure, expressed in the inability of these to transform testosterone into estrogens, thus depriving pituitary and hypothalamus from a proper steroidal milieu necessary to adequate functioning.