Types of leukemia in chronic benzene poisoning. A study in thirty-four patients.

The distribution of various types of leukemia due to chronic exposure to benzene is described in a series comprising 34 cases. The incidence of leukemia among 31 show-workers was 13.5/100,000. Acute myeloblastic leukemia was the most frequent type, followed by preleukemia, acute erythroleukemia and acute lymphoblastic leukemia. The extreme rarity of chronic myeloid leukemia was a noteworthy finding. The differences and similarities between the distribution of various types of leukemia in different series of patients with chronic exposure to benzene and ionizing radiation are discussed.