Cytomorphology

Cellularity and different distribution patterns can usually be assessed after careful study of the entire specimen under weak magnification. This is followed by an individual analysis of at least 100 cells from the peripheral blood and at least 200 cells from two representative areas of the bone marrow. More important than simply counting the material is its meticulous study by an experienced investigator based on the criteria of cell density, the ratio of erythropoiesis to granulopoiesis, distribution according to various maturity stages (in particular the blasts), mutations in the cytoplasm and nucleus, the eosinphil, basophil and monocyte count, megakaryocytes (quantitative and qualitative), as well as the distribution and fine structure of lymphocytes, plasma cells and reticulum cells. Moreover, the assessment also includes iron storage and cytochemical reactions (peroxidase and non-specific esterase) for the determination of blasts.