350 HYDATIFORM DEGENERATION IN TUBAL AND UTERINE PREGNANCY. 



can be recognized by examination with the binocular alone necessarily will depend 

 also upon the condition of the specimen. If the villi are matted, glued, or macerated, 

 not only the early hydatiform changes but even fairly advanced ones often are 

 masked so completely that recognition is difficult or impossible without histologic 

 examination. 



In many early specimens the diagnosis could be made at sight from a histologic 

 preparation under low magnification, even when it was impossible to make a diag- 

 nosis by examination with the binocular microscope alone. What makes this 

 possible is not, as has been generally assumed since Marchand's epochal work on 

 chorio-epithlioma, the appearance of the syncytium or that of the Langhans layer 

 or of the trophoblast, but the changes in the stroma which precede those in the 

 epithelium. The evidence in regard to this matter is overwhelming, and in the 

 early stages when the stroma already has been altered, it often is impossible to tell 

 whether the epithelial development is normally or abnormally active. Moreover, 

 in spite of Marchant's statement to the contrary, extremely large cysts often have 

 but a single smooth layer of epithelium. This has been asserted repeatedly by other 

 investigators also. The two layers of epithelium are not by any means always 

 present and, while there is no agreement in the matter, the opinion seems to be 

 that the grade of epithelial proliferation can not be used as a criterion for the deter- 

 mination of the presence of hydatiform degeneration. Menu said that the presence 

 of marked epithelial proliferation was emphasized early by Mliller (1847), Ercolani 

 (1876), Franque (1896), and Owry (1897); and according to Pazzi (1908 3 ), Ercolani 

 and Polano altogether denied the existence of connective tissue in the hydatiform 

 mole. The same tiling was asserted by Sfameni (1903), who claimed to have found 

 further evidence of the exclusively epithelial nature of the hydatiform mole in 1905. 

 According to Sfameni the hydatiform mole does not result from a modification of 

 existing chorionic villi, but from an entirely new growth which is wholly epithelial 

 in character! But this opinion, which was accepted also by Niosi (1906), seems to 

 exist among Italian writers only. 



Although Durante (1898) represented extremely long syncytial buds, he never- 

 theless found (1909) epithelial proliferation present only where certain vascular 

 changes were present. Winter (1907) stated that the condition of the epithelium 

 varies greatly, and Falgowski (1911) emphasized that he could not demonstrate 

 the presence of an increased epithelial proliferation or of vacuolation of the syn- 

 cytium. Aman (1916) also found that epithelial proliferation may be wholly absent. 

 Ballantyne (1913), on the contrary, found epithelial proliferation "so well developed 

 that it suggested that it is an essential process in the formation of the mole." 

 Ballantyne further likened hydatiform degeneration to edematous growths and 

 emphasized that both really are epithelial new growths. This opinion is accepted 

 also by de Snoo (1914), who regarded the hydatiform mole as a neoplasm of the 

 trophoblast with secondary changes in the stroma. 



There is no agreement at present as to whether the epithelial changes are 

 primary or secondary. As is well known, Marchand (1895) and Miiller, Ercolani, 

 and Langhans long before that regarded the epithelial changes as primary, but 



