Malignancy-induced lactic acidosis.

Lactic acidosis, a rare and usually fatal complication of malignancy, is defined as a clinical condition in which the pH is less than or equal to 7.35 and the serum lactate level greater than or equal to 5 mEq/L. We have described the clinical aspects of four cases of lactic acidosis associated with malignancy, and have reviewed all reported cases of lactic acidosis in malignancy meeting the criteria. Rapid recognition of the condition and prompt institution of chemotherapy led to reversal of lactic acidosis in three of our four patients, but long-term survival is related to the responsiveness of the underlying tumor.