A 48-year-old man complains of weakness and easy fatigability for 6 weeks. He has worked for 20 years in a chemical factory that produces a variety of plastics and other synthetic compounds. A complete blood count shows a hemoglobin level of 8.2 g/dL, WBC count of 45,000/mL, and a platelet count of 40,000/mL. Examination of a bone marrow aspirate reveals numerous malignant myeloblasts, and a diagnosis of acute myeloid leukemia is made. Exposure to which of the following agents is the most likely cause of this patient's hematologic disease?
Virtually all cases of acute and chronic benzene toxicity have occurred against the background of industrial exposure. Acute benzene poisoning primarily affects the central nervous system, and death results from respiratory failure. However, the long-term effects of benzene exposure have attracted the most attention. The bone marrow is the principal target in chronic benzene intoxication. Patients who develop hematologic abnormalities characteristically exhibit hypoplasia or aplasia of the bone marrow and pancytopenia. Aplastic anemia usually is seen while the workers are still exposed to high concentrations of benzene. In a substantial proportion of cases of benzene-induced anemias, acute myeloblastic leukemia develops. Overall, the risk of leukemia is increased 60-fold in workers exposed to the highest atmospheric concentrations of benzene. The other choices are not linked to the development of leukemia.Diagnosis: Acute myelogenous leukemia
Benzene
Benzopyrene
Carbon tetrachloride
Glycerin
Environment & Nutritional Pathology