Severe hypercalcaemia and extensive osteolytic lesions in an adult patient with T cell acute lymphoblastic leukaemia.

Hypercalcaemia is a rare feature of acute lymphoblastic leukaemia (ALL) in adults, particularly of the T cell type. We report on a 24-year-old patient with T-ALL, who presented with symptoms of hypercalcaemia (vomitus, acute renal failure), bone pain, extensive osteolytic lesions and normal white cell count without circulating blasts. An increased serum tumor necrosis factor (TNF-alpha) concentration of 35 pg/ml was found; it remained elevated at 52 pg/ml four weeks later, after having achieved haematological remission. Serum concentrations of IL-1beta, IL-6 and IL-2 were within the control range. The pathophysiology of hypercalcaemia in malignancy and possible mediators of bone resorption, in particular TNF-alpha, are discussed.