Myasthenia gravis in a patient with chronic myeloid leukemia treated by busulfan.

P.M., a seventy year old Polish-born male clerk, was referred to the Hematology Clinic in September 1963. Examination in another medical service in 1961 had revealed moderate hepatosplenomegaly, a platelet count of 900,000 per cu.mm. with normal red and white blood cell counts, and megakaryocytic hyperplasia in bone marrow with excessive platelet production and hyperplasia of the white cell series with a shift to the left but without blast cells. The diagnosis of primary thrombocythemia was made, and the possibility of transformation to myeloid leukemia was raised, but no specffic treatment was prescribed. Examination in our clinic in 1963 revealed hepatosplenomegaly, the spleen being palpated 6 cm. and the liver 2 cm. below the costal margin, both firm and nontender. Several enlarged nontender lymph glands of diameter up to 2 cm. were palpated in the neck and the axillae. The hemoglobin was 12.6 Cm. per cent, RBC 4,000,000 per cu.mm., hematocrit 40 per cent, reticulocyte count 0.1 per cent, and WBC 10,000 per cu.mm. with polymorphonuclears 65 per cent, band forms 4 per cent, eosinophils 4 per cent, blast cells 3 per cent, lymphocytes 24 per cent. The platelet count was 1,000,000 per cu.mm., bleeding tinue 6 mm., clotting time 5 mm., clot retraction normal, ESR (Westergren) 13 mm. in the first hour and 20 mm. in the second. The serum B1., level was 1250 m tg per ml., urea 42 mg. per cent, uric acid 6.5 mg. per cent. LE cells were not found. A sternal bone marrow biopsy smear was similar to the examination in 1961, except for the presence of a few blast coils. Leukocyte alkaline phosphatase staining showed a zero score. The clinical and hematologic findings were considered consistent with chronic myeloid leukemia. The patient refused treatment. In September 1964, his hemoglobin was 12.6 Cm. per cent, WBC 16,500 per cu.mm., with a normal differential count. The platelet count was 300,000 per cu.mm. The spleen, liver, and lymph glands were essentially unchanged since the previous examination.