HYDATIFORM DEGENERATION IN TUBAL PREGNANCY. 235 



vinced as to the occurrence of such a phenomenon. No one will deny that many 

 hydatiform chorionic vesicles are retained long after the death of the cyema. 

 The material with which I dealt suggested very plainly that even isolated villi 

 can and do survive a surprisingly long time; but Herzog (1898), from an examina- 

 tion of 7 tubal pregnancies, came to the conclusion that "chorionic villi degenerate 

 with astonishing rapidity after the death of the embryo. This appears to be 

 especially true of villi of young placentae." Although the use of the word placentae 

 suggests that Herzog really was not speaking of very young conceptuses, he never- 

 theless added that only the most intimate acquaintance enables one to recognize 

 villi after the embryo has been dead two or three weeks. 



As stated in the preceding chapter, the cyema usually is absent in older, large 

 hydatiform masses, only remnants of the chorionic membrane and villi remaining. 

 Were these hydatiform vesicles not retained, the cyema would not be missing in 

 any but possibly some extremely young vesicles, and if retention per se were the 

 cause of hydatiform degeneration, then the latter should not only be best de- 

 veloped, but also most frequent among those longest retained. This, however, is 

 not the case. Furthermore, the high incidence of hydatiform degeneration in tubal 

 pregnancies, to which attention was called by Meyer (1919 a ), also shows that long 

 retention is not necessary for the development of splendidly typical and universal 

 hydatiform degeneration. Some of the finest specimens were found among tubal 

 pregnancies in small chorionic vesicles in which cyemata still were present. If 

 retention alone were the sine qua non, then hydatiform degeneration should not 

 be so common under conditions which preclude long retention. Even Marchand 

 (1895) found it well to emphasize that "Nicht jedes abortiv-Ei wird zur Blasen- 

 mole, nicht jede Blasenmole zeigt denselben Grad der Epithel Wucherung." 



Werth further concluded that not one of the 7 cases of chorio-epithelioma 

 regarded as having arisen from tubal pregnancies recorded before 1904 was suffi- 

 ciently authenticated. Nevertheless, by 1910 Veit felt justified in saying that a 

 considerable number of cases of chorio-epithelioma arising from tubal pregnancies 

 had been described. He added that Risel (1895) gathered 11 cases from the litera- 

 ture and that a second case had been reoprted since Risel's paper. Since my interest 

 in the subject is largely incidental, I have not taken the trouble to gather from 

 the literature cases of chorio-epithelioma alleged to have arisen from tubal preg- 

 nancies which may have been reported since Veit wrote. Moreover, I could not 

 presume to judge these cases critically. Hence I will accept the fact that chorio- 

 epithelioma arising from tubal pregnancy is regarded as established by a number 

 of investigators. If the conception regarding the relation of chorio-epithelioma to 

 hydatiform mole is justified, then the occurrence of hydatiform degeneration in 

 tubal pregnancy must follow on a priori grounds alone. Moreover, whatever the 

 causes of hydatiform degeneration may be, one is possibly safe in assuming that the 

 condition is not restricted to the uterus, and when I noticed that hydatiform 

 degeneration was so very common in young uterine abortuses the surmise that it 

 might be still more common in cases of tubal pregnancy seemed justified. Since 

 over 100 specimens of tubal pregnancies from the Carnegie Collection were included 



