title: Occurrence of acute leukaemia in myeloproliferative disorders.
abstract: In a series of 306 cases of myeloproliferative disorders followed over a period of 21 years, 18 cases of well-documented acute leukaemia were encountered. Leukaemias were either acute myeloblastic or myelomonocytic and occurred from 6 months to 20 years after the initial diagnosis. Onset was relatively abrupt and the course rapidly fatal with with a median survival of 4 weeks. Due to the prolonged preleukaemic phase, it was possible to carry out a variety of clinical and laboratory observations. While no consistent features were noted, dysplastic haemopoiesis, a fall in leucocyte alkaline phosphatase activity, presence of Pelger-Hüet anomaly and other abnormalities suggest a disturbance in granulocytic maturation. These findings suggest that, following an initial injury to a pleuripotential haemopoietic stem cell, a prolonged 'latent' period occurs and, due to exposure to additional injurious agents or to a lack of cell regulating factors, acute leukaemia develops.
mesh_terms: D000328:Adult; D000368:Aged; D000469:Alkaline Phosphatase / Q000097:blood; D005260:Female; D006098:Granulocytes; D006801:Humans; D007951:Leukemia, Myeloid / Q000150:complications*; D015470:Leukemia, Myeloid, Acute / Q000150:complications*; D008297:Male; D008875:Middle Aged; D009196:Myeloproliferative Disorders / Q000150:complications*; D010381:Pelger-Huet Anomaly / Q000150:complications; D011087:Polycythemia Vera / Q000150:complications; D011289:Preleukemia / Q000097:blood; D055728:Primary Myelofibrosis / Q000150:complications
chemical_list: D000469:Alkaline Phosphatase