[Weakness, bone pain].

A 57-year-old man complains of a reduced exercise tolerance and bone pain for years. There is a past medical history of hyperuricemia and anemia of unknown etiology. In a routine examination a leukocytosis of 64,000 per ml, increased number of thrombocytes and an elevated level of lactic dehydrogenase is found. The suspected diagnosis of myeloproliferative disorder, in the present case of chronic myelogenous leukemia, is confirmed by a diminished neutrophil alkaline phosphatase activity, bone marrow biopsy and the demonstration of the Ph1 (Philadelphia) chromosome. Magnetic resonance imaging reveals an infiltration of the bone marrow. After the initial treatment with busulfan the white cell count is lowered.