Lactic acidosis and hypoglycemia in a patient with high-grade non-Hodgkin's lymphoma and elevated circulating TNF-alpha.

A 71-year-old patient with high-grade non-Hodgkin's lymphoma stage IVB, severe lactic acidosis and tumor-associated hypoglycemia is described. Endocrine causes of hypoglycemic episodes were excluded because of low serum concentrations of insulin and "insulin-like growth factor 1", and normal concentrations of growth hormone and thyroid hormone. Clinical conditions associated with lactic acidosis such as diabetes mellitus, biguanide intoxication, septicemia, acute hypoxemia, or circulatory insufficiency were ruled out. Enhanced glucose metabolism within the tumor was visualized by positron emission tomography employing 2-fluro-2-deoxy-D-glucose (FDG) as a tracer. A markedly elevated tumor necrosis factor-alpha (TNF-alpha) level was found which decreased after cytoreductive therapy paralleling the normalization of serum lactate. In contrast to the majority of cases of lymphoma-associated lactic acidoses reviewed to date, in our case lactate elimination was not reduced.