The relative infrequency of papillary carcinoma of the kidney proper reported in the literature is emphasized by Wohl1 in his description of a malignant papillary adenoma of the kidney. He says that his is the twelfth instance of such adenopapillary tumors appearing in the literature, but he probably has not included in this number a report by Eisenstaedt.2 The latter emphasizes the rarity of carcinoma of the renal parenchyma proper, and reports a tumor which in its microscopic characters resembles closely the one to be described. It contained papillae having very little supporting tissue, each pierced centrally by a thin-walled vessel. Kretschmer and Moody3 in 1914 reviewed the reports of such tumors and found ten recorded. They added another, making a total of eleven recorded at that time.
At a necropsy performed by me for the purpose of establishing the cause of death, a soft fleshy tumor was found in