Color Atlas of Hematology - Practical Microscopic and Clinical ...

56Normal Cells of the Blood and Hematopoietic OrgansQualitative and Quantitative Assessment of the Remaining Cells. Lymphocytecounts may be slightly raised in reactive processes, but a significantincrease suggests a disease of the lymphatic system. The exact classificationof these disease follows the criteria of lymphocyte morphology(Fig. 16). If elevated lymphocyte counts are found only in one preparationor within a circumscribed area, physiological lymph follicles in the bonemarrow are likely to be the source. In a borderline case, the histology andanalysis of lymphocyte surface markers yield more definitive data.Plasma cell counts are also slightly elevated in reactive processes andvery elevated in plasmacytoma. Reactive increase of lymphocytes andplasma cells with concomitant low counts in the other series is often anindication of panmyelopathy (aplastic anemia).Raised eosinophil and monocyte counts in bone marrow have the samediagnostic significance as in blood (p. 44).Megakaryocyte counts are reduced under the effects of all toxic stimulion bone marrow. Counts increase after bleeding, in essential thrombocytopenia(Werlhof syndrome), and in myeloproliferative diseases (chronicmyeloid leukemia, polycythemia, and essential thrombocythemia).Iron Staining of Erythropoietic Cells. Perls’ Prussian blue (also known asPerls’ acid ferrocyanide reaction) shows the presence of ferritin in 20–40%of all normoblasts, in the form of one to four small granules. The ironcontainingcells are called sideroblasts. Greater numbers of ferritingranules in normoblasts indicate a disorder of iron utilization (sideroachresia,especially in myelodysplasia), particularly when the granulesform a ring around the nucleus (ring sideroblasts). Perls’ Prussian blue reactionalso stains the diffuse iron precipitates in macrophages (Fig. 19 b).Under exogenous iron deficiency conditions the proportion of sideroblastsand iron-storing macrophages is reduced. However, if the shift iniron utilization is due to infectious and/or toxic conditions, the iron contentin normoblasts is reduced while the macrophages are loaded withiron to the point of saturation. In hemolytic conditions, the iron content ofnormoblasts is normal; it is elevated only in essential or symptomatic refractoryanemia (including megaloblastic anemia).