This condition is usually associated with tuberculosis elsewhere. Thus there is commonly tuberculosis of the ureter and bladder, and also, in the male, of the vesiculse seminales, vas deferens, and testicle. It seems probable that in most cases the tuberculosis originates in the testicle and travels to the other parts (Weigert), but an origin in the kidney itself is not to be excluded. The fact that the disease is rare in females would indicate that the propagation is usually from the testicle. renal phthisis is frequently associated with pulmonary phthisis, which is probably in most cases the primary affection.

The disease is usually very advanced in one kidney and absent or slight in the other. In the advanced cases the kidney is converted internally into a sac with irregularly ulcerated Avails, and divided partly into compartments by the remains of septa. The ulcerated surface presents some adhering caseous matter and the wall is infiltrated, the whole pelvis presenting the appearances shown in the lower part in Fig. 438. The capsule of the kidney is adherent. Hamill describes what he believes to be a case of tuberculosis of the kidney with complete destruction in a child of seven months, and gives summaries of recorded cases of this kind. He does not describe typical tubercles and did not find the bacillus.

In an early stage we find, it may be, the apex of a pyramid the seat of a small ulcer with yellow caseous walls, and with grey tubercles at the periphery in the substance of the pyramid. The lesion begins usually in the calices, frequently in those situated inferiprly, as in Fig. 438, and eats its way in, attacking and destroying the kidney tissue in its advance. There is a very irregular extension of the ulceration, but usually there is some indication of the calices preserved.

The Pelvis and Ureter partake in the tuberculosis, and the latter is often infiltrated either in patches or throughout. Its wall is greatly thickened, and its internal surface often presents an almost continuous layer of caseous matter.

Tuberculosis of kidney with hydronephrosis.

Fig. 438. - Tuberculosis of kidney with hydronephrosis. At lower part a ragged tubercular ulcer eating into kidney tissue. Two small isolated tubercular areas below. In upper part dilated calices (hydronephrosis). To right dilated ureter.

There is sometimes a partial Hydronephrosis (as in figure) along with the tuberculosis, from the caseous matter obstructing the ureter. It also happens sometimes that tuberculosis in one kidney is associated with hydronephrosis in the other. In such cases the tuberculosis of the bladder, affecting the orifice of the ureter, has caused obstruction of it and hydronephrosis has ensued.

The tuberculosis sometimes attacks a pervious branch of the Renal artery, and the tubercular virus is disseminated over the area of distribution of the artery. Hence it is not uncommon to find a larger or smaller wedge-shaped piece of kidney occupied by closely aggregated tubercles, while there is a comparatively slight tuberculosis of the pelvic portions. A general tuberculosis may develop from this.