Cancer of kidney, intramural, as seen after dividing the organ. (Israel.)
Hypernephroma.
—There is one peculiar variety of solid tumor of the kidney which deserves special mention, the so-called hypernephroma. These tumors consist essentially of adrenal tissue, although when they develop within the kidney their occurrence there is due to the presence of aberrant rests of the original suprarenal tissue. Gravitz, in 1883, was the first to recognize their real character. Supernumerary adrenal rests have been met with in many parts of the body, not alone in the kidney and perinephric tissue, but in the broad ligament, along the spermatic vessels, in the sexual glands of both sexes, in the liver, the mesentery, and even the solar and renal plexuses. Their occurrence in these localities may be explained by the close relationship between the mesonephros and the origins of these various organs. Hypernephroma has no pathognomonic signs or symptoms. It is usually a single tumor, although both kidneys have been affected. When the organ is not so involved as to mask all its original features the tumor will be found beneath the capsule, varying in size from that of a pea to that of a child’s head, its outer surface lobulated by depressed bands of capsule, its color lighter than that of the surrounding kidney texture, while projecting portions will be soft and almost cystic. When met with in other parts of the body its gross characteristics are essentially the same. Metastasis is very common, the tumor often extending along the walls of the veins, or even more often partially filling them than the lymphatics. A common method of extension also is by implantation within the peritoneal cavity; for the secondary implantation occurs most often along some portion of the urinary tract—e. g., the bladder.[66]
[66] It may assist in the recognition of hypernephromatous tissue, after removal, to remember that adrenal tissue has the property of decolorizing starch which has been turned blue by the addition of iodine. Crofton has shown how there may be put into a test-tube a 1 per cent. starch solution colored with a drop of weak tincture of iodine. If to this solution hypernephromatous tissue be added the blue color changes gradually to a pink and then fades out.
Fig. 639
Infiltrating form of cancer of the kidney. (Israel.)
Hematuria and renal colic are the most conspicuous features connected with the growth of these tumors. The former often occurs during sleep, and blood is passed in almost pure form, perhaps for a considerable period of time, after which spontaneous recovery apparently takes place, the trouble recurring at intervals.
There is but one method of treating hypernephromas, like other solid tumors, namely, by complete extirpation, i. e., nephrectomy. Even this may be too late, but should be undertaken, except in the most unpromising instances. If the existence of metastatic involvement can be determined even nephrectomy may be considered useless. (See chapter on [Cysts and Tumors].)