Histo- and immunomorphometry of megakaryopoiesis in chronic myeloid leukemia with myelofibrosis and so-called primary (idiopathic) osteo-myelofibrosis/-sclerosis.

A morphometric study was performed on trephine biopsies of bone marrow in patients with chronic myeloid leukemia (CML) accompanied by myelofibrosis and in so-called primary (idiopathic) osteomyelofibrosis/-sclerosis (OMF) to evaluate distinctive features of megakaryopoiesis. The periodic acid Schiff reaction (PAS) and a monoclonal antibody against glycoprotein IIIa were employed for the identification of megakaryocytes including precursor cells and Gomori's silver impregnation to determine the density of argyrophilic fibers. All patients with CML revealed a slight to moderate degree of medullary fibrosis and were compared with early hyperplastic stages of OMF showing an identical fiber count. Statistical analysis disclosed that distinctive features existed between these two subgroups. Amongst these variables were sizes of megakaryocytes and corresponding nuclei, frequency of bare nuclei, emperipolesis and numbers of isolated nuclear fragments as well as the circular deviation of cell and nuclear perimeters. Immunomorphometry also included immature elements (pro- and megakaryoblasts) of the megakaryocyte series. Consequently higher cell counts were calculable in both groups combined with smaller sizes and a more rounded aspect of nuclei. However, following immunostaining, significant differences in several megakaryocytic parameters (frequency, size, shape of nuclei) were still demonstrable between CML and OMF cases.