Experimental Production of Gynecomastia with Chorionic Gonadotropin *

The male mammary glands often undergo hyperplasia in the presence of tumors associated with a high urinary excretion of chorionic gonadotropin. Included in this group are the chorioepitheliomas, both testiculari'3 and extragenital,"" and, more rarely, teratomas"' and seminomas""' of the testis. Although the histological and clinical features differ in each of these tumors, there is reason to believe that all contain chorionic elements when accompanied by chorionic gonadotropin in the urine."2 Less commonly gynecomastia occurs in association with non-choriogenic tumors of the testis. These comprise a heterogeneous group with respect to their hormonal excretion patterns, but in general fall into one of two categories: (i) those in which the gynecomastia is probably a non-specific effect related to loss of testicular tissue by tumor invasion, radiation therapy, or surgical extirpation,' and in which the excretion of androgen is low and of follicle-stimulating gonadotropic hormone (FSH) high,' and (ii) those in which the gynecomastia appears to be more directly related to hormonal stimulation by the tumor itself, as in Sertoli-cell'0 and aberrant adrenocortical'1 tumors. In these the excretion of estrogen is increased, and since removal of the tumor results in both a reduction in urinary estrogen and a regression in the gynecomastia, it is highly probable that the tumor is the source of the estrogen and that the latter is an important factor in stimulating mammary growth. Gynecomastia has also been reported as a rare complication in interstitialor Leydig-cell tumors,"' but the histological diagnosis in such cases has been questioned.' As a rule these tumors produce virilization in children, but exert no hormonal effects in adults.3' On the basis of a study of dog tumors, Huggins and Moulder' have presented evidence to show that those testicular tumors associated with gynecomastia and previously reported as interstitial-cell tumors were probably incorrectly interpreted examples of Sertoli-cell tumors. However, in one of these cases, that of Hunt and Budd," the possibility of chorionic elements in the tumor does not appear to have been completely excluded, since the urine contained