A 30-year-old man presented in March 1954 with splenomegaly and CML in chronic phase was diagnosed. No specific treatment was given until October 1954 when his splenomegaly increased to 5 cm and his white cell count increased to 50 × 109/L. Fowler's solution 5 minims (1 minim = 0.06 mL, equivalent to 0.6 mg As2O3 ) three times daily was administered, resulting in a satisfactory control of his white cell count to about 10 × 109/L. Treatment was stopped. Six months later, he was readmitted with progressive splenomegaly (10 cm) and leucocytosis (211 × 109/L). Fowler's solution was recommenced at 5 minims three times daily, and increased to 10 minims three times daily. This resulted in gradual control of his white cell count. The dose of As2O3 was decreased to a maintenance dose of 5 minims three times daily. However, 8 months later, signs and symptoms of chronic arsenic poisoning developed, including skin pigmentation, diarrhea, and chronic gastrointestinal hemorrhage. As2O3 was stopped and he was put on melphalan. Splenomegaly and leucocytosis progressed despite treatment, and he died 11 months later of pneumonia. The maximum daily dose (10 minims × 3) of As2O3 given orally was 18 mg, which is comparable to 10 mg/d when used intravenously for the treatment of relapsed APL.
