HYDATIFORM DEGENERATION IN TUBAL AND UTERINE PREGNANCY. 351 



most investigators seem to have come to the opposite conclusion. Some share the 

 opinion of Schroeder that hydatiform degeneration points to a stimulus resulting 

 in hyperplasia of the entire chorionic villus. Nor is there agreement as to what the 

 initial changes are. Durante (1909) regarded the presence of vessels with an imper- 

 fect endothelial lining and with thick infiltrated walls as the initial lesion in hydati- 

 form degeneration. These changes were noted by him, especially in trunk villi, 

 and epithelial proliferation was most evident where the vascular lesions were most 

 pronounced. Durante further stated that the chain form of the hydatids is due to 

 the fact that the vascular lesions occur at intervals along the villus. Unfortunately, 

 the structure of long hydatiform villi does not confirm such an explanation nor 

 Durante 's conclusion that the hydatid cavities within the villi result from dilatation 

 of the capillaries. Many investigators report the early disappearance of the blood- 

 vessels, a phenomenon which some regard as secondary and others as primary to 

 the death of the embryo. 



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 to-day, 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 epithelium 

 usually is least in the young villi, and he should have added 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 incipient 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. 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 whatever 

 its status may be and the malignant hydatiform mole, or chorio-epithelioma. 

 Such a conclusion alone presupposes the existence of the widest differences in the 



