Warburg Effect Presenting as Refractory Type B Lactic Acidosis: A Pediatric Case Report

Type B lactic acidosis is a rare but life-threatening metabolic complication of hematologic malignancies, attributed to the Warburg effect, in which tumor cells preferentially generate energy through aerobic glycolysis despite adequate oxygen availability.Although increasingly recognized in adults, pediatric cases remain uncommon and are associated with high mortality.A 12-year-old boy with early isolated marrow relapse of high-risk precursor B acute lymphoblastic leukemia (B-ALL) developed rapidly progressive lactic acidosis and recurrent hypoglycemia during re-induction chemotherapy.Despite extensive investigations, no alternative etiology was identified, including hypoxemia, endocrinopathy, inborn errors of metabolism, or significant hepatic or renal dysfunction at the onset of lactic acidosis.Repeated microbiological investigations remained negative throughout the clinical course.Repeat bone marrow aspiration and biopsy demonstrated refractory leukemia with 70% blasts, supporting a diagnosis of malignancy-associated type B lactic acidosis consistent with the Warburg effect.Despite aggressive supportive care, corticosteroid cytoreduction, and subsequent anti-CD22-targeted therapy with inotuzumab, the metabolic derangement persisted in parallel with progressive leukemia, resulting in multiorgan dysfunction and death.This case highlights that persistent lactic acidosis with refractory hypoglycemia arising during re-induction therapy may be an early indicator of refractory disease rather than treatment-related toxicity or occult infection.Malignancy-associated type B lactic acidosis should be considered after more common etiologies have been excluded.Early recognition may facilitate timely initiation of definitive anti-leukemic therapy, which remains the cornerstone of management despite the overall poor prognosis.