Type A versus type B Lactic Acidosis in the context of undiagnosed B-cell lymphoma

Lactic acidosis, characterised by an imbalance between lactate production and clearance, is classified into type A and type B. Type A is associated with tissue hypoxia and shock, while type B occurs without hypoxia, often due to metabolic disturbances, such as cancer-related metabolic reprogramming, known as the Warburg effect. This case series presents two patients with undiagnosed B-cell lymphoma who exhibited distinct forms of lactic acidosis. The first patient, with septic shock and end-organ hypoperfusion, developed type A lactic acidosis, with escalating lactate levels despite aggressive resuscitation. The second patient, with stable haemodynamics but persistently elevated lactate, exhibited type B lactic acidosis, likely due to the Warburg effect of lymphoma. These cases underscore the importance of differentiating between type A and type B lactic acidosis, as the underlying aetiology guides treatment strategies. Early recognition of the cause is crucial for optimal management and patient outcomes, particularly in malignancy-associated metabolic disturbances.