Complete Text (Part 28)

of sections picked to pieces, the granular epithelium of the convoluted tubules appears still more granular, the nuclei are less distinct, and the granules cause these tubules to appear as if tinted with India ink. If upon the addition of acetic acid the granules mostly disap- pear, it is proof that they were albuminoid in character. The further the process advances the greater is the swell- ing, softening, and opacity of the cortex, while the former gray appearance of the convoluted tubules becomes more yellow. The granules within the cells increase, and do not disappear upon the addition of caustic potash or soda, their fatty nature being thus indicated. 14 210 DIAGNOSIS IN PATHOLOGICAL ANATOMY. Such a kidney, as a whole, is very considerably enlarged, flaccid, and soft, and isolated groups of convoluted tubules may be seen upon the surface as yellowish spots, which are prominent when contrasted with the perfectly opaque gray- ish-yellow ground substance. When the kidney is laid open the cortex appears thickened and swollen, projecting beyond the pyramidal portion. The tubules of Ferrein are to be recognized as gray, often as still translucent lines, while the region of the convoluted tubules appears opaque and is trav- ersed by clear, yellow streaks and spots, the fatty degener- ated tubules. The vessels of the cortex are usually but slightly injected, while those of the pyramidal portion are very full, so that a contrast in the color of the two regions becomes very apparent, especially when viewed from a short distance. Amyloid degeneration is frequently associated with parenchymatous nephritis, in which case the glomeruli, as has already been stated, appear upon the cut surface as translu- cent, vitreous, enlarged granules, and assume a brown color upon the addition of iodine. Sufficiently thin sections for microscopic examination may be obtained with a razor, by placing the half or even a smaller portion of such a kidney over the forefinger, and mak- ing it tense with the middle finger on one side and the thumb on the other. The double knife works still better, by which sections made perpendicularly through the cortex and pyramidal portion, furnish a very good general view when examined with a low power. It may be thus recog- nized that the process, even when very severe, is limited al- most exclusively to the convoluted tubules, which are some- times continuously fatty degenerated, while again (and this is most frequently the case) the degeneration appears in spots. The contrast produced by transmitted light, between the translucent pyramids of Ferrein and the dark appearance of the convoluted tubules furnishes quite a characteristic picture. The condition which is known as granular atrophy is re- garded by Virchow as the third stage of parenchymatous THE KIDNEYS. 211 nephritis. When the epithelial cells are completely fatty degenerated, the detritus may be absorbed, the canals then naturally collapse, their tunicse proprise, which undergo a fibrous degeneration, become united and form a hard cica- tricial mass, which occupies much less space than the paren- chyma from which it was formed, and when seen from the surface is much deeper than the surrounding portion. The projections are still relatively normal, not wholly so, because their frequent yellow color indicates that here also a fatty degeneration of the urinary tubules has taken place. The vascular coils in the atrophic places become obliterated, shrink, and finally are changed into little clumps of connec- tive tissue, which sometimes become impregnated with lime salts, and consequently^ appear, even to the naked eye, as yellowish-white points. Upon microscopic examination they appear black, as the lime does not allow the light to pass through. Upon the addition of a little hydrochloric acid the black mass completely dissolves with the development of gas- bubbles. (5.) By interstitial nephritis is understood an inflamma- tion which runs its course essentially in the interstitial (inter- tubular) tissue, although the proper glandular tissue also appears to be affected. Two forms are to be distinguished : (1.) the fibrous, generally of a chronic character ; (2.) the purulent, running an acute course. The first form, when total, as in the parenchymatous affec- tion, produces an enlargement of the cortical portion, which, however, presents a more uniform grayish-white appearance, as the contrast between the tubules of Ferrein and the region of the convoluted tubes disappears more or less. In micro- scopic sections, collections of granulation cells may be seen, especially about the glomeruli, and also between the urinary tubules which have become pressed apart. A certain num- ber of cases occur in which the inflammatory changes are situated almost wholly within the capsules of the glomeruli, so that they become converted into rounded masses of gran- ulation tissue (nephritis inter stitialis glomerulo-capsularis). 212 . DIAGNOSIS IN PATHOLOGICAL ANATOMY. This affection must not be confounded with that first de- scribed by Klebs, as glomerulo-nephritis, in which the in- flammation is situated between the coils of the glomeruli, in the connective tissue which is there in small amount and which is provided with stellate cells. In a later stage the round cells become more and more spindle-shaped, then transformed into fibrous tissue, and thus a kind of cicatrix is formed within, which all the tissues perish; the epithelial cells become fatty, the tunic« proprise are fused, the glom- eruli become converted into little connective tissue clamps so that nothing remains but a tough fibrous tissue. The kidney as a whole appears atrophied, but possesses a smooth surface ; on section the cortical portion is especially atrophied and consequently of increased consistency. Remnants of urinary tubules are still present, which appear as yellow lines and points between the gray masses of connective tissue. The above description applies to those cases in which the inflammation is total, where the entire kidney is affected. Fibrous interstitial nephritis also occurs very frequently as a circumscribed affection, usually multiple, the result being a number of cicatricial depressions upon the surface of varied size, and corresponding with which wedge-shaped depressions of the cortex are usually seen when the section of the kidney is examined ; these depressed portions and less frequently a corresponding part of the pyramid are converted into a gray- ish-white, dense, fibrous (cicatricial) tissue. Microscopic ex- amination shows that the same changes have taken place as were previously described. This form of inflammation (ne- phritis inter stitialis cTiro7iica fibrosa multiplex) occurs in syphilis, and a kidney that has undergone this change ought always to arouse suspicions of this disease, although the latter can never be diagnosticated from this affection alone. Cica- trices which have resulted from old hasmorrhagic infarctions bear a great resemblance to those of syphilitic origin, and cases will frequently occur where it will be impossible to make a differential diagnosis from this local condition alone. The appearance of the other parts of the body must then be THE KIDNEYS. 213 taken into consideration. In other cases the local affection furnishes a point for differentiation. The syphilitic scars are always of a gray color, while brownish, greenish, or blackish flakes of blood-pigment remain for a long time in those re- sulting from hsemorrhage. Although circumscribed interstitial nephritis occurs most frequently in the cortical portion, still it is not altogether absent from the pyramids, where, for instance, according to Virchow, the gray fibromata arise from such a circumscribed inflammation, as the urinary tubules may be followed into them. These vary in size from that of a millet-grain to that of a pea, and may be easily distinguished from tubercles by the absence of cheesy degeneration. The interstitial inflam- mation is frequently situated within the papillse (nephritis interstitialis papillaris) apparent by their gray color. The pyramids are also a favorite seat for cysts caused by chronic interstitial inflammation. These are large or small, the former being produced by the confluence of smaller ones, as may be recognized by the projections upon their walls. In the earlier stages of the affection, several small cystic en- largements may be seen with the microscope, situated along the course of a single tubule, the interior of which is filled with a peculiar glistening gelatinous mass. The second form of interstitial inflammation is what is known as purulent interstitial nephritis., which tends from the beginning to interstitial suppuration. Certain varieties of this affection constitute metastatic nephritis, which is produced by septic emboli and is characterized by the ap- pearance of metastatic abscesses. These rarely attain a large size and are usually situated in the cortical portion, though sometimes in the pyramids. In the latter case, however, they are never found within the apices of the papillae, but rather in the middle and outer portions. The contents of the little abscesses are not composed of actual pus, but of disintegrated, fatty degenerated glandular tissue. It often happens in this affection (for instance in connection with en- docarditis ulcerosa) that it is possible to recognize micrococci 214 DIAGNOSIS IN PATHOLOGICAL ANAT03IY. in the centre of each abscess ; they may lie in the glomeruli, in other vessels, in the urinary tubules, or in the interstitial tissue. When sections made with the double knife are first soaked in absolute alcohol and ether, then in acetic acid, and finally are tinged with aniline-violet, the micrococci will assume a beautiful blue color, while all the fat, which is produced in large quantities in the surrounding tissues by parenchymatous inflammation, is dissolved. To this class belong a number of varieties of inflammation which result from disease of the urinary tract, and which produce at the outset changes in the pyramidal portion. Such alterations consist of small yellow lines which often contain spherical enlargements, and which follow the course of the urinary tubules from the apices of the papillee towards the periphery. On the surface of the papillae a tough, grayish, diphtheritic infiltration is often found. A little later the cortical portion becomes involved, when the striped appearance of the ab- scess is less marked, and it assumes more the form of a cir- cumscribed collection of pus. It has already been stated that the abscesses appear on the surface as small yellow points of the size of a millet- grain, and are arranged in small groups. . On examining the surface of the section, they may usually be followed through the cortical into the pyramidal portion ; still it is not always possible to discover that the affection of the two portions is continuous. When larger abscesses have formed in the re- nal tissue they may rupture into the calices, when a suppu- rating ulcer is formed (j)hthisis renalis purulenta). It was precisely in this affection, spreading from the pelvis to the kidney, and associated with marked alteration in the mucous membrane of the former and of the calices (hence called 'pyelo-nejoh.ritis)^ that Klebs first recognized the constant ap- pearance of lower organisms. The disease almost always accompanies inflammatory and often actually diphtheritic processes in the bladder, being considered as the direct re- sult of a wandering of the organisms along the ureters and renal pelves into the urinary tubules. The results here, as THE KIDNEYS. 215 in case of embolic affection, are not abscesses properly speak- ing, but the pus is mingled with the products of fatty and broken-down epithelial cells, and frequently there may be no real pus formed at all. Careful examination shows that the urinary tubules are completely plugged, and even distended, with micrococci ; that the epithelial cells, not only of these but of the neighboring tubules, are fatty degenerated, and that only finally a zone of interstitial suppuration surrounds these centres. There is, however, another affection quite similar to the preceding, as far as the local trouble is concerned, and which agrees etiologically also, as micrococci are always found in the centres of inflammation. In certain diseases, especially in those of a septic nature, and when moreover there is no local cause for metastasis, yellowish, or frequently yellowish- brown, linear or round spots of inflammation are seen within the pyramids and especially in the papillse (nephritis papil- laris diplitheriticci) ; these are very similar to those already described, and upon microscopic examination are seen to be composed of three constituents, — micrococci which lie within the tubules or vessels, fatty degenerated epithelial cells of the former, and an inflammatory infiltration of the surround- ing tissue. Such preparations deserve careful attention, as they are especially fitted to illustrate the difference between micrococci and fat granules. The former are small and uniform in size, lying at equal distances from each other, and present a sharp and dark contour ; the fat granules on the contrary are of unequal size, lying at unequal distances from each other, and disappear when treated with glacial acetic acid, alcohol, and ether. It is clear that in this affection the organisms come from the blood, as the urinary tract is unaltered while the glomeruli and other vessels are filled with micrococci. (c.) The last form of renal inflammation to be considered is the catarrhal (nephritis catarrhalis), which affects princi- pally the trunks of the straight tubules (tubes of Bellini). The bundles of straight tubules within the pyramids and 216 DIAGNOSIS IN PATHOLOGICAL ANATOMY. also the tubiiles of Ferrein appear widened, their translucent gray is changed into an opaque gray or grayish-white color, and it is possible to press out of the papillae a large quantity of milky fluid of a cloudy gray or grayish-yellow color ; with the microscope this is found to contain numerous large and small cells, free nuclei and detritus, with only comparatively few cells of ordinarj^ size. It is possible to distinguish by examining this fluid, the gray color of the papillae caused by catarrhal inflammation from that due to the interstitial form, as in the latter affection it is possible to press out only a very small quantity of fluid and cells. In connection with the inflammatory processes may be mentioned the microscopic masses contained in the urinary tubules, and known as casts (liyaline casts., incorrectly called fibrinous). They occur both in the straight and looped tubules, and those in the latter sometimes undergo amyloid degeneration. They are often best seen with a low power, when they may be recognized by their peculiar fatty lustre. The casts extend into the cortical portion only in extreme cases. 0. The different forms of renal infarction are to be con- sidered in concluding the subject of the inflammatory pro- cesses, especially those of the papillse. Four forms are to be distinguished, — the lime, the uric acid, the haematoidine, and the bilirubine infarction. The first occurs only in adults, the second and fourth in children only, and the third in both, though under very peculiar conditions in adults. (a.) Lime infarctions appear in the form of white lines, which radiate from the apex of the papilla and extend as far as the middle of the pyramid, or even further. Upon section, especially when made transversely (with the double knife), very small lime granules appear, either free in the in- terior of the tubules, or, as is more frequently the case, de- posited in the walls of the same. Upon the addition of hy- drochloric acid they become dissolved with the evolution of gas. The deposition of the granules takes place not only within the straight tubules but also in the looped ones, and TEE KIDNEYS. 217 on this account these kidneys are particularly fitted to show the loops of Henle in the easiest manner possible. Lime in- farctions always indicate interstitial inflammation. (5.) Uric acid infarctions occur only in very 3^oung chil- dren, usually in the first week of life, still they have been observed in the sixth' week, and even later. Their presence has an important medico-legal bearing, as they are found almost exclusively in children who have breathed. These infarctions appear as yellow, brick-red, or yellowish-red lines extending from the papillae ; similar yellow lines are only rarely seen in the cortical portion. By tearing apart a small bit of the papilla, or pressing the epithelium out of the straight tubules, it will be seen that they are completely filled with a mass that appears either light or dark-brown by transmitted light, and yellow or rose-red by reflected light. These masses are dissolved by the addition of hydrochloric or acetic acid, crystals of uric acid being formed upon the evaporation of the resulting solution. When examined with the microscope, the mass is found to be composed of glob- ules of varied size, often in pairs, and covered upon their surface with thorn-like projections (urate of ammonia). The other uric acid salts (soda) occur less frequently. The urates are found exclusively in the urinary tubules. ((?.) Hoematoidine infarctions appear in adults only under very peculiar conditions (after transfusion of blood from the lower animals, burns, etc.). Masses are then found in the papillae, filling the tubules, which appear like brown lines, and are composed, in recent cases, of course, of blood corpus- cles. In cases of long standing they consist of blood pig- ment. According to Virchow the hsematoidine infarctions in the new-born, present a clear brown, brownish, or reddish- brown color, and consist of a deposition of yellowish-red or reddish-brown granular or crystalline hsematoidine, which appears both in the canal of the tubules and in their epi- thelial cells. The coloring matter is due to small haemor- rhages. (c?.) Bilirubine infarctions are of more frequent occur- 218 DIAGNOSIS IN PATHOLOGICAL ANATOMY. rence, either alone or combined (the usual form) with uric acid infarction. They occur only in the new-born, in those that were jaundiced. The pigment has the form of rhombic tablets, of fine needles often arranged in arborescent or stel- late groups, and of clumps which occur both in the interior of the tubules, in the epithelial lining, in the intertubular tissue, and especially in the vessels. Their principal seat is in the papillse, but in cases of great intensity they are not wanting in the cortical portion. (The same crystals appear, though not constantly, in the blood, and in