the cortex may separate through the middle zone, forming a cavity suggesting a cyst. This is probably in part a post-mortem production.

Pigmentation is observed in the cells of the medullary portion in persons of advanced age.

Amyloid degeneration occurs in connection with amyloid disease of other organs. The suprarenal body becomes hard and of a grayish, translucent appearance. The degeneration affects the walls of the blood-vessels, from which it extends to the connective tissue. The glandular portions suffer pressure-atrophy. The cortex is more frequently involved than the medulla.

INFECTIOUS DISEASES.

Tuberculosis of the suprarenal body is the most important of its diseases. Miliary tubercles may be met with in cases of general tuberculosis, but a fibrocaseous form of the disease is more frequent and of much greater significance. The gland is enlarged, sometimes reaching the size of an egg; it is hard and usually rather nodular, or irregular in outline. The capsule is thickened, and the substance of the gland is composed of dry, yellowish cheesy matter, or of a puriform material (Fig. 267). In the later stages the caseous or puriform matter may be absorbed, and fibrous-tissue growth may convert the entire body into a shrivelled, hard mass of connective tissue. Sometimes one gland alone is involved; more frequently the disease occurs bilaterally. Tuberculosis of this form may be primary, but usually is secondary to tuberculosis of the lungs, intestines, or other organs. The general effects of this disease will be discussed below (see Addison's Disease).

Syphilis occurs in the form of gummata. Uniform fatty degeneration

FIG. 267.-Caseous tuberculosis of the suprarenal body (Kast and Rumpel).

of the suprarenal body has been met with in congenital syphilis.

CIRCULATORY DISTURBANCES.

Hemorrhage is comparatively rare. It may occur in association with hemorrhagic diseases, or severe anemias, especially leukemia. Sometimes it is caused by traumatism, or by obstruc

tion of the venous circulation. The hemorrhage may be inconsiderable, or may be quite large. In the latter instances secondary rupture of the hematoma may cause death by intraperitoneal hemorrhage, or a hemorrhagic cyst may result.

INFLAMMATION.

Inflammation of the suprarenal body is very rare. A simple and a hemorrhagic form have, however, been described. Abscess may occur in consequence of pyemia, or as a secondary condition following other forms of suprarenal disease.

TUMORS.

Sarcoma is the most frequent form of tumor. Melanotic, as well as unpigmented, varieties are met with. The tumor may reach considerable size, and may destroy the gland completely. Adenoma and carcinoma may arise from the cells of the acini. Histologically these tumors resemble the normal gland in their structure, and the term adenoma is perhaps more suitable than carcinoma. The tumor occurs as a nodular, irregular growth, often of a yellowish or brownish color; it most frequently arises from the cortical portion of the gland.

Gliomata of the suprarenal bodies have been described, but it is doubtful whether these tumors are true gliomata. Neuroma is a rare form of suprarenal disease.

Secondary sarcoma and carcinoma are not infrequent.

Tumors of the cortex of the kidney, having the structure of suprarenal tissue, are described under Tumors of the Kidneys.

GENERAL EFFECTS OF SUPRARENAL DISEASES.

It is

The physiology of the suprarenal body is still obscure. quite generally believed, however, that this gland holds some relation to pigment-formation, as well as to the circulation, either through the action of substances elaborated within the gland or through the nervous system. The last is suggested by the abundance of nervous tissue in the gland.

Addison's disease, in which fibrocaseous tuberculosis of the suprarenal bodies is commonly present, is an affection characterized by brownish pigmentation of the skin of exposed parts of the body (face, neck, and hands), and of the skin in the flexures of the joints, or in other parts subjected to pressure. The pigmentation usually occurs in a mottled form at first, but soon becomes uniform. Brownish or purplish spots upon the mucous membranes (mouth) are not unusual. Besides pigmentation the characteristic symptoms are great weakness, disturbances of the stomach (vomiting), and cardiovascular asthenia.

Though fibrocaseous tuberculosis of the suprarenal gland is discovered in many cases, Addison's disease may occur in association with other affections of the suprarenal, such as tumors; and it may be absent despite the existence of tuberculosis or of other diseases of both of the glands. The absence of Addison's disease in the latter cases has been explained by some writers by the assumption that the suprarenal disease had not existed long enough for the development of the symptoms of Addison's disease. Occasionally alterations in the sympathetic nervous system (semilunar ganglia and solar plexus) have been discovered when the suprarenal glands were apparently normal. No explanation of such cases can be made. It must be accepted at the present time that the suprarenal bodies are in some way concerned in the etiology of the disease. The disease of the gland need not, however, be of any special sort.

CHAPTER VII.

DISEASES OF THE URINARY ORGANS.

THE KIDNEYS.

CONGENITAL ANOMALIES.

ABSENCE of one of the kidneys is frequently observed. Occasionally one kidney, instead of being completely absent, is atrophic or hypoplastic. The opposite kidney may undergo compensatory hypertrophy. Both kidneys may be wanting in certain monstros

ities.

Congenital lobulation is quite common, and is usually bilateral. The kidney is divided into separate lobes by furrows of variable depth. Occasionally there is almost complete separation into numerous lobules.

A few instances have been observed in which there was a third kidney, and usually in these cases two of the kidneys lying to one side of the spinal column were agglutinated.

Fusion of the two kidneys may occur, and there may result a single large organ, with a double pelvis and ureter lying to one or the other side, or a horseshoe-kidney may be formed. In the latter

the two organs, which are generally displaced far downward, are united at their lower ends by a commissure passing across the spine just above the lumbosacral junction. The commissure may consist of normal kidney-tissue, or may be fibrous; more commonly the former.

Congenital cysts and other congenital diseases will be referred to below.

CHANGES OF POSITION.

Congenital Malposition.-Not rarely one of the kidneys is displaced downward. It may even occupy the pelvis. In other cases it is displaced laterally or forward, and may be found imme diately beneath the anterior abdominal walls.

Acquired malpositions may result from pressure upon the organ, or from elongation of the peritoneal reflections covering the kidney and absorption of the perirenal fat. The right kidney is more frequently displaced than the left, and the condition is especially common in women. Repeated pregnancies, the effects of tight lacing, and diseases or displacement of the liver are prominent causes. Movability or displacement of the kidney may be but a part of a general visceral descent (enteroptosis).

Several grades of movability or displacement may be distinguished. In the first, the perirenal fat is wanting, and the kidney is more movable beneath its peritoneal covering than is normal. This occurs in a large proportion of women, and usually affects the right kidney. In more advanced grades the peritoneal reflection covering the kidney is elongated and considerable movability of the organ within the abdomen results. The kidney may be moved from side to side, downward as far as the pelvis in some cases, or upward to the normal position or under the ribs. In a third group of cases the kidney, lying within an elongated peritoneal pouch, is retained in an abnormal position by adhesions.

Results. Twisting of the pedicle may lead to serious circulatory disturbances, and twisting of the ureter to retention of urine, sometimes causing hydronephrosis. Pressure of the displaced right kidney upon the duodenum may lead to dilatation of the stomach.

CIRCULATORY DISTURBANCES.

Anemia of the kidney may occur as a part of general anemia. The kidney is light in color and rather hard in the earlier stages; but if the anemia persists degenerative softening and enlargement

may ensue.

Complete arrest of the blood-supply, produced experimentally, leads to rapid necrosis of the kidney, the organ becoming ashen

gray in color and of a homogeneous structure, so that the separate parts (cortex, medulla, pyramids) are indistinguishable. Near the cortex, where some circulation is maintained by the capsular vessels, fatty degeneration is observed. Somewhat similar changes are met with in circumscribed areas in diseases in which the circulation in branches of the renal artery is obstructed (see Embolism).

Active hyperemia of the kidney is generally a part of acute inflammation. It may result from irritant chemical poisons or from the toxic action of infectious poisons. The kidney is enlarged, dark red in color, and on section the cortical substance is found to be swollen and marked by dark-red points-the Malpighian bodies. Sometimes punctate or linear hemorrhages may be observed. The urine is somewhat albuminous, and hyaline casts occur. It is difficult to draw a sharp line between this condition and acute nephritis.

Passive hyperemia occurs in cardiac and pulmonary diseases which impede the circulation, or as a consequence of thrombosis of the inferior vena cava or renal veins, or of other local causes obstructing the circulation in the renal veins. The kidney is enlarged and on section the cortex is found to be swollen, the substance of the kidney dark red in color, particularly in the pyramids in the vicinity of the large veins. The Malpighian bodies may be distinctly enlarged and dark red.

Long-standing passive congestion leads to reactive hyperplasia of the interstitial connective tissue of the organ, and thus to a form of secondary interstitial nephritis. In these cases the kidney becomes contracted, the surface somewhat irregular, and the capsule ofttimes adherent. The organ may be intensely hard and pigmented, and the term cyanotic induration is appropriate.

The urine in passive hyperemia is, as a rule, deficient in quantity, and contains variable quantities of albumin and hyaline or granular tube-casts.

Hemorrhage.-Punctate hemorrhages may occur in cases of intense active or passive hyperemia, the extravasation of blood occurring in the interstitial tissues, in the uriniferous tubules, or within the capsule of Bowman. Similar hemorrhages may be observed in acute or chronic nephritis. In these cases the extravasation of blood may occur by diapedesis or by actual rupture of the capillaries. Small hemorrhages may occur in the perirenal tissues in certain of the hemorrhagic diseases. Large hemorrhages occur within the kidney-substance only in cases of traumatism.

Edema of the kidney results from obstruction of its venous circulation. The kidney becomes enlarged and soft, and the spaces between the convoluted tubules (the primary lymphatic spaces) are distinctly enlarged. There is associated congestion in these cases. Simple edema of the kidney may result from obstruction of the urinary outflow.