[Hypercalcemia of T-cell leukemia in adults].

A retrospective study of 26 adults with acute T-cell leukemia showed that 14 patients (54%) had hypercalcemia at some point of the disease. Hypercalcemia was found at presentation in nine patients and revealed the disease in one. Eight patients had hypercalcemia at the time of death. Serum phosphorus and parathyroid hormone levels were normal. All patients with hypercalcemia tested positive for the HTLV-1 by Elisa and Western blot. Six patients had focalized or diffuse lytic roentgenographic bone lesions. Hypercalcemia in acute T-cell leukemia may involve production of interleukin-1-alpha and parathyroid hormone-related protein by HTLV-1-infected cells.