[Genetic origin of malignant hematopoiesis well defined]

It is vital to determine which cell lines are affected in haematological malignancies, since such information is important to an understanding of the biology of neoplastic stem cells and their capacity to differentiate and mature. Parallel studies of cellular morphology and of chromosomal anomalies is an approach permitting determination of lineage specificity for different haematological neoplasms. Findings in current studies suggest that acute myeloid leukaemia and myelodysplastic disorders generally involve cells of myeloid lineage only, whereas myeloproliferative disorders may also involve lymphoid cell lines. Lymphoid malignancies such as non-Hodgkin's disease or acute lymphoid leukaemia usually involve lymphoid cell lines.