Lactic acidosis is pathophysiologically classified into type A and type B. The latter is a rare but potentially life-threatening emergency, mainly described in hematological malignancies. The association between Type B lactic acidosis and malignancy is known as the Warburg effect. Patients with the Warburg effect have a very poor prognosis. Herein, we report a case of gastric diffuse large B-cell lymphoma (DLBCL) with severe lactic acidosis and hypoglycemia owing to the Warburg effect that were effectively treated by prompt introduction of chemotherapy. A 73-year-old woman with a 2-month history of abdominal distension was referred to us for suspected peritoneal cancer. Pathological examination revealed gastric DLBCL with peritoneal dissemination. After hospitalization, blood test results revealed prolonged hypoglycemia, with a blood sugar level of 50–70 mg/dL; severe lactic acidosis with pH 7.166; lactate level 12.7 mmol/L; and base excess −21.0 mEq/L, despite continuous administration of glucose and sodium bicarbonate. The cause of lactic acidosis and/or hypoglycemia was considered to be the Warburg effect. We initiated a 50% reduced-dose CHOP (cyclophosphamide, vincristine, doxorubicin, prednisolone) chemotherapy regimen without rituximab until information on the CD20-positive status was available. During chemotherapy, acidosis, hypoglycemia, and impaired consciousness promptly improved. If lactic acidosis or hypoglycemia is present in patients with malignant tumors, it is important to suspect the possibility of the Warburg effect and to introduce cancer treatment as soon as possible.
Uncovering molecular abnormalities leading to the Warburg effect in primary refractory diffuse large B-cell lymphoma
