HYDATIFORM DEGENERATION IN UTERINE PREGNANCY. 219 



In the course of this investigation a villus with a normal stroma and normal 

 vascularization never was found to have undergone true hydatiform degeneration, 

 but one with a normally active epithelium both Langhans layer and syncytium 

 often was truly hydatiform. That is, it not only was watery in appearance, but also 

 fusiform or globular, even in external form. In fact, Marchand (1895) himself found 

 that "Das Epithel welches die Zotten und ihre Anschwellungen bekleidet zeigt 

 ein sehr verschiedenes Verhalten." Yet even today the feeling on the part of 

 many seems to be that unless a marked hyperplasia of the Langhans layer and of 

 the syncytium is present the condition is not one of hydatiform mole. This position 

 seems to me to be untenable, for, as Marchand himself said, the change in epithe- 

 lium usually is least in the young villi, and it must be added that it is unrecognizable 

 in the early stages and in young conceptuses. A perusal of the literature descrip- 

 tive of the actual cases leaves little doubt upon this point, and a careful study of 

 the advent of the earliest recognizable changes in hydatiform mole is absolutely 

 convincing. The earliest recognizable, even if not the incipient, changes occur in 

 the stroma and in the vessels and not in the epithelium. In passing, it may be 

 noted that although Marchand stated that the change in the epithelium is primary, 

 he nevertheless somewhat contradictorily added that the most important fact is 

 the degenerative change in the stroma of the villi. 



Although not applicable to what I have come to regard as the incipent changes 

 in hydatiform degeneration, it nevertheless is true that the stroma often, if not 

 always, quite early becomes hydatiform that is, glassy or clear, though not 

 necessarily watery. Moreover, the villous vessels often degenerate or disappear 

 completely at a very early stage. 



Various grades of hydatiform degeneration with vitreous stroma and vessels 

 in various stages of disappearance are shown in figures 110 (No. 977), 111 (No. 

 516), 112 (No. 8746), and 113 (No. 396). The first and last of these specimens 

 are in a splendid state of preservation, so that maceration changes really can be 

 wholly eliminated. It is exceedingly difficult to make any definite statement 

 as to what is typical regarding the epithelium. This has been said by others 

 also. Indeed, this necessarily follows from the fact, agreed to by every one, that 

 histologically there is no true line of demarcation between the ordinary benign 

 hydatiform mole, the so-called destructive benign (?) hydatiform mole, what- 

 ever its status may be, and the malignant l^datiform mole or chorio-epithe- 

 lioma. Such a conclusion alone presupposes the existence of the widest differences 

 in the condition of the epithelium in these cases, and that such differences actually 

 exist is beyond question. 



Marchand's revolutionary investigation on chorio-epithelioma notwithstand- 

 ing, the epithelium is not always two-layered, nor is it always thickened, in hydati- 

 form mole. That the epithelium can not always be active beyond the normal 

 follows also from the fact that the proliferative changes in it are subsequent to, 

 even if not necessarily consequent upon, changes in the stroma. Furthermore, 

 like the latter, they are gradual in their evolution and may stop or be stopped at 

 any stage of their development. Then, too, the condition of the epithelium 



