Ewing's sarcoma as a cause of the syndrome of inappropriate secretion of antidiuretic hormone.

A patient with Ewing's sarcoma presented with the syndrome of inappropriate secretion of antidiuretic hormone (SIADH) (1). Plasma values for vasopressin were found to be over four times the normal values expected for the plasma osmolality. At postmortem examination, the arginine vasopressin concentration in the tumor tissue was ten times that of the plasma. These data suggest that Ewing's sarcoma may cause SIADH.