A system of practical medicine. By American authors. Vol. 4

by Unknown

I do not think that either the lesions or the symptoms are such as to justify such views. After separating the true cases of chronic parenchymatous nephritis—cases in which only the epithelium of the tubes and of the Malpighian capsules is changed—all the other kidneys of chronic Bright's disease present essentially the same lesions and give rise to the same symptoms.

We can indeed often tell during the life of the patient whether he has large white or atrophied or waxy kidneys, but in many cases such a diagnosis is impossible.

MORBID ANATOMY.—There is good deal of variety in the gross appearances and size of the kidneys. Most numerous are the so-called atrophied kidneys. These kidneys are usually diminished in weight, the kidneys weighing together three or four ounces, but often they weigh up to ten or twelve ounces. The capsules are adherent, and when they are stripped off portions of the kidney-tissue adhere to them. After stripping off the capsules the surface of the kidney is left finely or coarsely nodular. The cortex is thinned and of a red or grayish mottled color; the pyramids are small or of normal size, sometimes studded with small white concretions of urate of soda. There are often small cysts both in the cortex and pyramids.

Next in frequency come the so-called large white kidneys. Of these a certain number are not examples of chronic diffuse nephritis at all, but of acute or chronic parenchymatous nephritis. Of the large white kidneys which belong to chronic diffuse nephritis we can distinguish three varieties—the simple large white, the waxy large white, and the large white of cardiac disease.

The gross appearance of the kidneys is very much the same whether they are or are not the seat of waxy infiltrations. They are increased in size, weighing together from sixteen to twenty ounces. The capsules are not adherent; the surfaces of the kidneys are smooth and pale, often mottled by large stellate veins. The cortex is thickened, of white or white mottled with red, or yellow or grayish color. In the very waxy kidneys the gray or white color has a semi-translucent appearance. The pyramids are large and red, contrasting with the cortex. We find some kidneys of the same color and general appearance as large white kidneys, but with atrophied cortex and adherent capsules.

The large white kidneys due to cardiac disease are increased in size and weight. The capsules are not adherent, the surfaces are smooth. The cortex is thickened and of a peculiar pinkish-white color; the cortical striæ may still be visible. The pyramids are of a somewhat darker red than the cortex. The whole coloring is entirely different from that of chronic congestion of the kidneys, and the texture, although firm, is not of the stony hardness of that lesion.

Besides the atrophied and the large white kidneys, there are a large number of kidneys which are not diminished in weight and which do not resemble either the large white or the atrophied kidneys. These kidneys weigh together from nine to twenty ounces. The capsules are sometimes adherent, sometimes not. The surface of the cortex may look like that of a normal kidney or be finely or coarsely nodular. The cortex is of normal thickness or thickened; it is of a variety of colors. Sometimes it is not to be distinguished from a normal kidney, or it may be gray or gray mottled with yellow or red or white, or of a diffuse red color. The pyramids are of natural size or large, of red or pale color. I do not know a good name for these kidneys, but their appearance differs altogether from that of the large white or atrophied kidneys.

Still another class may be made of those kidneys which pass from the condition of chronic congestion into that of chronic diffuse nephritis. These kidneys retain the color and the hardness of chronic congestion, but the capsules are adherent, the surfaces finely nodular, and the cortex irregular.

Minute Lesions.—Nearly all the component parts of the kidneys undergo morbid changes. In the tubes the epithelial cells undergo marked changes, especially in the cortex. The epithelial cells are swollen, finely or coarsely granular, or fatty or completely disintegrated, or the seat of hyaline degeneration. They may be detached from the walls of the tubes, or sometimes they are in place, but flattened. The tubes may contain cast-matter, blood, pus-cells, small polygonal cells. The calibre of the tubes is often changed. The tubes may be dilated either in the form of cylindrical or sacculated dilatations; the latter often form cysts of considerable size. Such dilatations regularly affect groups of tubes, as if they were due to obstruction of the large tubes in the pyramids. In other cases the tubes are denuded of epithelium, become smaller, fall together, and look like connective tissue. The membranous wall of the tubules may be thickened or it may undergo waxy degeneration.

The Malpighian bodies are changed. Their capsules may be thickened, contracted, or dilated. The flat cells which line the capsules are increased in size, sometimes in number. The capillary tuft may be dilated or its walls may be thickened; it may be completely obliterated and changed into a ball of fibrous tissue, or it may be the seat of waxy infiltration. Often the Malpighian bodies are much closer together than they are in a normal kidney.