240 Tumors o£ the Testis 



in gonadotropic hormone output subsequently suggested this possibility, and 

 this was proved at autopsy in both patients. In a third patient no nodule could 

 be palpated in the testicle but a large retroperitoneal mass was found, as well 

 as gynecomastia, and the urine contained 200,000 R.U. of hormone. Biopsy 

 demonstrated chorioncpithelioma. 



Biochemistry 



Careful hormonal studies were made on all our patients both before and 

 after operation. We are indebted to Dr. Herbert M. Evans, who has made all 

 recent assays of the urine, for his interest in this subject and his help in 

 correlating the clinical with the biochemical studies. Briefly, the routine 

 method of testing the urine is to get a collection (for 24 hours or longer) from 

 which the gonadotrophin is concentrated by the Levin-Tyndale method of 

 precipitation with tannic acid. Normal immature female rats, 25 or 26 days 

 old, are used and two groups of three animals each are utilized for the test. 

 Over a period of four days aliquot portions of powder derived from a known 

 amount of urine are injected into each animal and autopsy is performed on 

 the fifth day. A positive test is one which shows follicular or uterine stimula- 

 tion. Each animal of the first group is injected with a concentrated powder 

 equivalent to 100 cc. of native urine. Rats of the second group are injected 

 with the amount of powder derived from 4 cc. of urine. If these rats show no 

 response there are fewer than 10 R.U. per liter of urine. If the animals com- 

 prising the first group show a positive reaction, while those of the second group 

 are not stimulated, there are between 10 and 250 R.U. per liter of urine. If 

 both groups of rats react positively there are over 250 R.U. per liter, and fur- 

 ther tests are performed with varying dilutions of native urine in order to 

 detei'mine accurately the number of units. By this method normal men are 

 found to excrete fewer than 20 R.U. and usually fewer than 10 R.U. per liter 

 of urine. Table 1 gives a summary of the results obtained by the use of this 

 test on 44 recent patients with testicular tumor. Clinically the test has proved 

 of no diagnostic value with this exception: when it shows 10,000 R.U. or more 

 of gonadotrophin per liter of urine, the diagnosis of chorioncpithelioma is 

 justified. So uniformly is the high output related to this type of tumor that in 

 some localities, particularly Copenhagen, it is accepted as a fact that chorion- 

 epithelioma is the only type of tumor which causes the excretion of this hor- 

 mone and that, whenever it is present in abnormal amounts, search in the 

 growth or the metastases will disclose chorionic elements. In those patients 

 in whom the test was positive before castration, subsequent testing of the 

 urine has considerable value in prognosis. When the gonadotrophic output 

 is correlated with both the pathological type of tumor and the presence or 

 absence of mestastases a fairly accurate prognosis is possible. 



