PATHOLOGICAL ANATOMY OF THE TESTICLE 489 



almost, indeed, as a rule, undergo malignant degeneration. This degen- 

 eration may take the form of a cylindrical epithelioma, invading the 

 tissues and filling the cysts with papillomatous masses, or large or small 

 round cell or spindle cell sarcoma, or finally of vegetative masses, con- 

 sisting of a loose edematous stroma surrounded by syncytial masses, 

 exactly like chorionic villi. These masses erode blood vessels, and the 

 tumors are exceedingly malignant, metastasizing early to every part of 

 the body. They are known as chorio-epitheliomata or choriomata. Che- 

 vassu has described similar, less well defined structures in tumors in 

 which they form only a small part of the mass, but in which their power 

 to erode blood vessels is apparent. In all malignant degenerations of 

 embryomata, the malignant process soon dominates the clinical and path- 

 ological picture. 



Tumors of the testicle represent, according to different statistics, one 

 two, or three per cent of all tumors. Chevassu reports, among 128 cases, 

 sixty-two embryomas, fifty-nine seminomas, and seven miscellaneous. 

 They are most frequent in subjects at the period of maximum sexual 

 activity, being rare below eighteen and above fifty. Forty-two cases of 

 malignant tumors in infants have been collected, all varieties being repre- 

 sented. Embryomata are more frequent from eighteen to thirty-five, and 

 seminomata from thirty-five to fifty. In general, therefore, they are more 

 precocious than the tumors of any other organ. The two sides are in- 

 volved with about equal frequency, and the condition is practically always 

 unilateral. Heredity and traumatism seem to play little part in the 

 causation of these tumors. Their malignancy is indicated by the fact 

 that among cases followed for several years, castration cured one seminoma 

 in three, and one mixed tumor in sixteen. The failure of early recognition 

 is largely responsible for the unfavorable results. 



Metastatic Tumors. Metastases of malignant tumors to the testis are 

 rare. They occur oftenest with melanotic carcinoma, and less frequently 

 with sarcoma and carcinoma, 



Lymphosarcoma. The testicle may be involved in a lymphosarcoma- 

 tous process. 



