Lactic acidosis and renal enlargement at diagnosis and relapse of acute lymphoblastic leukemia.

Bilateral renal enlargement was noted on ultrasonography during an extensive renal evaluation for severe hypokalemic metabolic acidosis with an increased anion gap in a 12-year-old Hispanic boy who had normal results of a physical examination and complete blood count. The patient was found to have acute lymphoblastic leukemia. Resolution of the lactic acidosis and bilateral renal enlargement occurred with initiation of chemotherapy and recurred with each subsequent relapse.