The diagnosis of hematological neoplasias is based on cytomorphology and histology. They are used to complete diagnosis, classify diseases and to assess prognoses over the course of treatment. In this regard, cytomorphology mainly involves the assessment of panoptical staining and a variety of cytochemical stains in blood and bone marrow smears. Cytomorphological assessment permits the description and distinction of malignant and healthy cells.
Between 4 and 6 unstained bone marrow or peripheral blood smears (anticoagulant: EDTA or citrate) are needed for cytomorphology. Bone marrow is usually the test material of choice. Material for cytomorphology can also be submitted in syringes containing EDTA anticoagulant for preparation of the smears, but should arrive at the laboratory within 24 hours if at all possible.
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.
Measurement uncertainty describes the scatter of measurement findings. These deviations occur in every stage of analysis. We conduct regular monitoring and take suitable action to recognize the extent of deviation and fluctuation in good time and to restrict these factors to within the prescribed tolerances. On request, we can communicate the individual measurement uncertainty when needed for a meaningful interpretation of our laboratory findings.