334 HYDATIFORM DEGENERATION IN TUBAL AND UTERINE PREGNANCY. 



Relatively little syncytium is present, but the trophoblast invades the muscularis 

 in many places and a good deal of coagulum is present, most of it apparently having 

 arisen from degeneration changes in the stroma of the mucosa and from similar 

 changes in the trophoblast and the muscularis. The latter is moderately invaded 

 by round cells. No remnant of the wall of the chorionic vesicle or of the amnion or 

 embryo could be detected in the sections examined, both evidently having been 

 absorbed completely, only some of the villi remaining behind; or, the chorionic 

 vesicle may have been aborted and these villi left implanted within the tube. 



Some exceedingly fine hydatiform villous trees were found among the speci- 

 mens in this group. Scaffoldings or frameworks formed by proliferating syncytium 

 arising from the epithelium of the chorionic membrane also were seen. Since the 

 syncytial buds were found far out on proliferations of trophoblast which capped the 

 villi, and also in the center of trophoblastic nodules, the origin of the syncytium 

 from the Langhans layer would seem to be again and exceptionally well confirmed. 

 In some cases a detached hydatiform villus was fastened by opposite extremities 

 to two portions of the tube wall. It is well to remember, however, that one of these 

 attachments probably was gained before the separation of the particular villus 

 from the chorionic vesicle. 



Of the 36 cases remaining in this group of chorionic vesicles without amnion, 

 after deducting 8 (7 of which belong in group 1 and 1 in group 2), 50 per cent 

 showed the presence of undoubted hydatiform degeneration and in 1 additional 

 case its existence was doubtful. 



Since only a few specimens are contained in each of the last five groups, I shall 

 treat them as one. Among 28 specimens remaining in these groups 12, or 43 per 

 cent, showed the presence of hydatiform degeneration and 4 others were doubtful. 

 From this percentage it is evident that the incidence of hydatiform degeneration 

 among tubal specimens seems to increase with advancing age of the conceptus 

 rather than decrease, as will be emphasized in connection with the uterine specimens 

 to be considered later. This probably can be attributed to the fact that the speci- 

 mens in the first group are composed of villi only, and that many of the empty 

 chorionic vesicles in group 2 were detached from the wall of the tube by hemorrhage 

 before hydatiform degeneration had developed sufficiently to enable me to recognize 

 it. Moreover, it must be remembered that all tubal specimens, no matter in what 

 group they are classified, are in fact young specimens, and since those falling in the 

 latter groups succeeded in maintaining a foothold in spite of repeated hemorrhages, 

 a larger number of them might be expected rightly to show the presence of a hydati- 

 form change. 



The incidence of hydatiform degeneration in the 104 tubal pregnancies classed 

 as pathologic is 44, or 42.3 per cent of the whole. This is a somewhat higher inci- 

 dence than was obtained in the 348 uterine abortuses classed as pathologic, and 

 may be accounted for partly, or wholly even, by the greater incidence of young 

 specimens in the tubal series. That the tubal specimens undoubtedly were younger 

 follows from common knowledge regarding tubal pregnancies alone, but it also is 

 shown by the average menstrual ages, which were 43.4 days in 25 tubal, as compared 



