Paraneoplastic hypokalemia in acute myeloid leukemia: a case of renin activity in AML blast cells.

Hypokalemia due to renal potassium loss has frequently been observed in patients with acute myeloid leukemia (AML). The pathogenic mechanism for this hyperkaluresis is unclear. In this report we describe a patient with AML FAB M4, in whom the clinical course, the electrolyte disturbances, the serum aldosterone levels, and the diffuse hyperplasia of the adrenal cortex documented a typical case of marked secondary hyperaldosteronism. On analysis of the leukemic cells of this patient compared with normal bone marrow cells, a significant increase of renin-like activity in the cytosol of the blast cells was noted. Activation of the renin-angiotensin-aldosterone system by paraneoplastic production of renin-like activity in AML blast cells might contribute to the hypokalemia often observed in patients with acute myeloid leukemia.