HYPERTROPHY.
Hypertrophy and ffdema of the Plamda.—These two lesions, which are inseparable, are due to an increase in number and volume of the elements constituting the villosities, together with an exudation of fluid material between these elements. The epithelial covering remains in tact, though it is hypertrophied to cover the enlarged villi; but the other structures may be profoundly modified. The cells of the mucoid tissue are hypertrophied and increased in number, and are closely aggregated together, one or two vessels still retaining their normal calibre. In more advanced degrees of change, the vessels disappear entirely from the mu coid tissue. Within the epithelial layer are a large number of round cells, dentate, and with fusiform prolongations, and even star-shaped; in other words, we find a true myxoma of the mucoid tissue. De Sit:L(1y considers this the first stage in the development of the vesicular mole. Ercolani, as we have seen, regards this lesion as a hyaline transformation, because few cells thus changed can be found in the parenchyma of the villus, while the amorphous and transparent element is abundant; and Wilde luts seen the trunks that were not dilated by fluid undergo a fatty degeneration. In a case of acute hydramnion in a twin pregnancy, de Sinky, who examined the placenta, found in it the following alterations: "Even with the naked eye it was possible to distinguish two different parts of the organ; the one being violet red and filled with blood, and the other looking pale yellow and thin. The fluid appeared to be everywhere between the membranes, though the contents of the amniotic cavity did not seem to be increased. The membranes were easily detachable from one another. Histological examination of hardened sections allowed that the red portion exhibited a considerable dilatation and engorgement of the blood spaces, while the villosities appeared normal. In the white part,
on the other hand, the walls of the maternal vessels were hypertrophied, and there was no blood in them. The villosities had but few vessels, and they were bloodleas. There were seen certain dilatations of the mucoid tissue reticulum, which contained an amorphous material not colorable by either picro-carminate of ammonia or by purpurine.
" Some of these spaces contained a large cell which almost entirely filled it. In most villosities of the white portion of the placenta, the cellular elements were much more numerous than is normal. Some villosities had become fibrous, or, more rarely, fatty. The epithelial covering was notably hypertrophied, and was thus much more apparent than in the red part. The cord was apparently normal. The vein and one of the arteries contained blood-cells; but the other artery was contracted, and almost obliterated, and contained no blood; it only had a few small round elements, which were colorable by reagents, and appeared to be due to endothelial proliferation. The intima was infiltrated with these same elements, showing the existence of endarteritis. In the healthy artery we could see, in the midst of the blood globules, a certain number of giant cells of various shapes. They appeared also in the vein, but less abundantly, and mostly rounded. The stroma of the cord and its covering were nor mal. In short, the lesion consist xl of a partial cedema of the placenta, together with complete antemia of that region, probably of maternal origin. Although I do not consider the lesion a specific one, I must add that I have seen similar lesions in cases of syphilitic placenta." There was no syphilis in either the patient or her husband. '