[Histopathology of chronic myeloid leukemia in diagnostic biopsies of bone marrow]

Histopathology of the bone marrow of diagnostic biopsies prior to any therapy is described in a total of 412 Ph1-positive patients. Special attention is paid to the distribution of megakaryocytes, increase of fibres and blasts, and occurrence of storing histiocytes of pseudo-Gaucher type. Megakaryocytes were significantly increased in 31.6% of diagnostic biopsies, myelofibrosis was found in 15.8%, significant increase of blasts in 2.4%. Pseudo-Gaucher cells were detected in 57.8% of a total of 412 biopsies. These histiological features are considered as an indication of the progress of the disease. A semiquantitative specification of CML by this criteria is described which can be performed rather reliably and defines the stage of CML at diagnosis prior to substantial treatment.