Abstract
Lactic acidosis is a rare complication of malignant neoplasms first described in patients with acute leukemia in 1963. Since then, there hasbeen seen more often, particularly in hematological malignancies and rarely in solid tumors. Wereport the case of a 53 years old male with lactacidosis B1 and gastric Burkitt lymphoma whowas admitted to the hospital with constitutionalsymptoms, weight loss, diarrhea and melena.Arterial blood gases revealed a metabolic acidosis with increased anion gap (pH:7,278; HCO3-:9,1mmol/l; AG: 20) and elevated lactate (15,5mmol/l). Other causes of lactacidosis, as circula-tory failure, sepsis and shock were ruledout. Common causes of type B lactic acidosiswere also excluded, such as infections, diabetesmellitus, renal failure, liver failure, thiaminedeficiency, drugs and toxins.