Abstract
A 54-year-old male presented with possible sepsis and elevated serum lactic acid (LA) of 18.7 mmol/L. Despite the sepsis treatment protocol and the management of other causes of type A lactic acidosis, his LA remained elevated. Herein, we present a case of type B lactic acidosis in the setting of a diffuse large B cell lymphoma. The proposed mechanisms of persistent lactic acidosis in malignancy are highlighted in this case report.