Acute lymphoblastic leukemia in a patient with pituitary dwarfism under treatment with growth hormone.

An 18-year-old male with pituitary dwarfism, who had been on replacement of growth hormone (GH) and thyroxine for 3.5 years, developed acute lymphoblastic leukemia (ALL). The GH replacement was discontinued, and he was treated with a conventional protocol for ALL. A complete remission was obtained after 10 weeks. Maintenance chemotherapy was given with reduced doses (1/4 to 1/2) of cytotoxic drugs. The platelet count soon reached 200,000/microL, but the hemoglobin level and white blood cell count improved only slowly, reaching 10.0 g/dL and 1,500/microL, respectively, after five months. He has been in complete remission with a hypocellular bone marrow for nearly 15 months. Since GH can stimulate the proliferation of some normal and leukemic hemato-lymphoid cells, the slow remission induction and the prolonged anemia and leukocytopenia after remission, may have been related to the absence of GH in this patient.