Polycythemia and renal carcinoma

Ten patients with polycythemia and renal carcinoma are presented and twelve previously documented cases from the literature summarized. The syndrome occurred in some 4.4 per cent of 205 patients with polycythemia and 2.6 per cent of 350 patients with renal carcinoma seen in the Presbyterian Hospital. The renal tumors, as well as adjacent parenchymal tissues, were not histologically unique in the six specimens studied. The polycythemia was, for the most part, a simple erythrocytosis without marked splenomegaly, leukocytosis or thrombocytosis. It thus resembled "secondary" rather than primary polycythemia except that it was not dependent upon arterial oxygen unsaturation. Two of our patients had complete hematologic remission following nephrectomy, one for two years and the other for eleven years. Two others from the literature had similar remissions for fourteen months and three years. Of the twenty-two patients thus far described, all eight who underwent nephrectomy had subsequent hematologic remission, whether or not other factors may have played a part. The polycythemia can therefore be regarded as secondary to the renal tumor, as maintained by previous authors. A similar erythropoietic effect has been described for uterine myoma and cerebellar hemangioblastoma, as well as benign renal adenoma and several varieties of carcinoma. The mechanism for the erythrocytosis is unknown, but probably an erythropoietic substance is produced, perhaps in the tumor or in the neighboring renal parenchyma. Whatever the mechanism and its site of action, the appreciable coincidence of polycythemia and renal carcinoma makes mandatory the urologic investigation of hematuria in polycythemia.