The cases of suppurative pyelo-nephritis complicating tubercular disease and calculi in the pelvis of the kidney will be considered when discussing these diseases.

Pathology and Symptoms.-1. Abscesses produced by emboli may occur in the course of pyæmia and malignant endocarditis. Both kidneys are large, congested, and studded with small abscesses. The blocking of small terminal arteries by the emboli causes pyramidal areas of white infarctions which subsequently break down to form abscesses.

The symptoms of embolic abscesses in the kidney are obscured by those of the primary disease. Pus may not appear in the urine, as the abscesses seldom communicate with the urinary tubules.

2. Idiopathic abscesses occur without assignable cause, and it is unknown whether the suppuration begins first in the kidney or in its pelvis. One kidney becomes partially destroyed, and in the remaining portion abscesses are found. The pelvis of the kidney is inflamed and becomes distended with pus, constituting a pyonephrosis. The suppurative processes may extend to the perinephritic tissues. The symptoms are at first obscure:

(a) Pus-symptoms are present, consisting of irregular fever, erratic chills, and cold sweatings. The symptoms of septicæmia or of the typhoid condition may become marked, or the patient will develop the waxy changes in the visceral that regularly accompany prolonged suppuration.

(b) Symptoms of a localized abscess consist of pain and tenderness over the kidney.

(c) Pus and broken-down kidney-tissue are present in the urine. The urine is frequently acid, the pus is uniformly mixed with the urine, and the character of the urine is unchanged after the bladder has been washed out. From time to time the pus escapes from the dilated pelvis in large quantities and appears in the urine.

(d) There may be a tumor, appreciable by palpation should the pelvis of the kidney be sufficiently distended by pus. The tumor may become reduced in size by the escape of pus in large quantities down the ureters.

3. Suppurative Pyelonephritis from Cystitis.—Both kidneys are swollen, congested, and studded with small foci of inflammation. The pelvis of the kidney is inflamed and coated with fibrin and pus. By the confluence of the suppurative foci large portions of the kidneys are converted to abscesses. The ureters may be normal or they may be inflamed. The lesions of an acute or chronic cystitis are almost always present.

In some cases there is an antecedent history of cystitis. At the time of the kidney-infection, the patient will develop septic symptoms-repeated chills and irregular fever with prostration. The urine will be diminished and will contain pus and blood from the bladder or kidney or from both. In some cases the urine is altogether suppressed. Prostration becomes more extreme, and the patient dies with pyæmic or septic symptoms.

4. According to Delafield, suppurative nephritis following cystitis due to enlarged prostate presents a different clinical picture. The patients are men, usually over fifty years of age, who have suffered from cystitis and an enlarged prostate gland. The first symptom is a diminished quantity of urine containing blood, or blood alone may seem to be passed. In other cases the urine is altogether suppressed. The patient becomes restless, anxious, and shows an increasing prostration; there are usually no chills, and there may be no fever. The patient may either die in collapse within a few days or may die from septic poisoning.

The prognosis is always fatal if both kidneys be involved. If one kidney alone be the seat of abscess, it may be removed and the patient may recover.

Treatment. The preventive treatment is directed toward the cystitis and toward strict asepsis in all operations upon the urinary organs. When symptoms of suppurative nephritis occur, it is of the greatest importance to decide whether one or both kidneys be involved. The position of localized tenderness is to be considered, but the surest method of settling the question is by cystoscopic examination. If by the cystoscope purulent urine be seen to flow from both ureters, operative treatment is of no avail. If the pus be seen to flow from one ureter alone, the prospects of recovery after the operation are rendered more probable.

TUMORS OF THE KIDNEY.

Benign tumors consist of fibroma, lipoma, lymphadenoma, and adenoma. These benign growths are of little clinical interest.

Malignant tumors are sarcoma and carcinoma.

Sarcoma may occur in adult life, but it is more frequent in young children, and not infrequently it occurs as a congenital tumor. The ordinary form of sarcoma is the smallcelled variety; a rarer form, usually of congenital origin, is the rhabdo-myoma, which consists of sarcoma and striped muscular fibre. Sarcoma of the kidney grows rapidly, is very vascular, and frequently breaks down in places to form cysts containing blood and clots.

Carcinoma is usually of the encephaloid variety, and so frequently shows an alveolar structure that it has been described as "malignant adenoma."

Secondary cancer of the kidney is not uncommon, with a primary growth situated in the testicle or the prostate gland. In the secondary form both kidneys are usually studded with small isolated nodules.

Primary malignant growths of the kidney frequently reach enormous dimensions, so as to cause symptoms by pressure

upon the abdominal organs.

Pressure on the ureter fre

quently results in a hydronephrosis. Secondary deposits

FIG. 49.-Sarcoma of kidney. Perfect health after operation (Abbe).

may occur by extension or metastasis.

Symptoms consist of pain and tenderness, hæmaturia, cancerous cachexia, and the presence of an abdominal tumor. Pain and tenderness are not constantly present. The pain may be steady and dull, radiating to the groin and the thigh, or there may be a paroxysmal pain, due to the passage of a blood-clot down the ureter, resembling the pain of renal colic.

Hæmaturia occurs in about half the cases, and may be the first symptom noticed. The blood, There may be bloodof the ureter; these The blood is usually

when present, is usually constant. casts of the pelvis of the kidney and casts are very characteristic of cancer. passed in small quantities, although exhausting or even fatal hemorrhages may occur.

The symptoms of malignant cachexia become progressively marked. Anæmia is rendered more profound by the occurrence of hemorrhage; emaciation is extreme, and is in marked contrast to the enlarged abdomen.

The tumor is at first located in the region of the kidney,

but it tends later to invade the whole abdominal cavity. It may be distinguished by the following peculiarities: (a) The surface often presents a series of convexities or knobs; (b) there is no respiratory movement of the growth, and (c) the hand may usually be thrust between it and the free border of the ribs; (d) the growth is not movable, as is a floating kidney; (c) percussion shows the colon passing in front of the growth; (f) a tympanitic zone is usually detected by percussion between the liver and the neoplasm; (g) rapidgrowing tumors may yield a sense of fluctuation; (h) the renal tumor can usually be traced deeply into the loin. In children the diagnosis of the growth from retroperitoneal sarcoma may be impossible.

The duration of malignant growths of the kidney is variable. The congenital cases may terminate fatally within a few weeks after birth. Usually in children the course is more rapid and malignant than in adults, seldom extending over one year. More rarely the disease may exist for a number of years before death occurs.

The prognosis is uniformly bad unless an early and successful nephrectomy be performed.

Treatment. The results of nephrectomy for sarcoma in children are not good. The operation, however, should be performed if the diagnosis be made early in the disease, and in cases in which the disease is limited to the kidney. In adults the results of the operation are somewhat more encouraging. The risks of the operation itself are great, shock and hemorrhage being the imminent dangers encountered.

CYSTS OF THE KIDNEY.

Etiology and Pathology.-Small retention-cysts of the kidney are common in chronic nephritis; they may also occur in comparatively healthy kidneys.