A new dimension to the endocrine role of the kidney has been added in recent years with the demonstration of an apparent causal relationship between a group of renal disorders and a form of absolute polycythemia. Moreover, a renewed interest in the problem of the humoral control of erythropoiesis has resulted in general acceptance of a serum factor responsive to fluctuations of arterial oxygen saturation in the homeostatic control of erythropoiesis. Although the locus of origin of this erythropoietic stimulating factor remains in some dispute, the preponderant evidence points to the kidney as the major, if not the only site, for its production.
A selective review of the literature, with rejection of a few cases which do not furnish adequate criteria, discloses polycythemia in association with 50 cases of hypernephroma,1-9,29,30,31 1 case of adenoma,10 5 cases of hydronephrosis,3,11-13 4 cases of polycystic disease,1 and one case