Primary disseminated form of Ewing sarcoma in association with hypercalcemia and acute renal failure.

We present a case of an extremely rare form of Ewing sarcoma--primary disseminated, with fulminating course, severe hypercalcemia, extensive calcium deposition in parenchymatous organs, including kidneys, and acute renal failure as a clinical consequence. Correction of hypercalcemia was followed by prompt restoration of the glomerular filtration rate (GFR), suggesting that hypercalcemia had a direct effect on its regulation independent of the renal tubular damage. The effectiveness of the treatment with indomethacin indirectly supports the possibility of prostaglandin-mediated humoral hypercalcemia of malignancy.