Although FLOW cytometry has not been integrated into MDS diagnostic procedures from the very beginning of MDS research, there is growing evidence that FLOW cytometry adds valuable information with regard to diagnosis and prognosis.
Bone marrow (BM) histology provides additional information including BM cellularity and stromal reactions, e.g. fibrosis. Immunohistochemistry may help to identify the presence of CD34-positive clusters and BM progenitor cells with strong p53 staining which has been associated with adverse outcome.
Cytogenetic analysis is not only necessary from the diagnostic point of view but enables us to get important prognostic and therapeutic information. The new cytogenetic risk groups will be explained in detail with special regard to cytogenetic abnormalities correlated with specific MDS-subtypes.
New publications indicated that mutation status in MDS might be clinically very important and in particular, that specific mutations predict survival independent of other variables. Mutations specific for some MDS-subtypes will be discussed as well as their clinical relevance.
Fluorescence in situ hybridization (FISH) analyses are helpful to clarify complex aberrations and can be used for in case of dry taps to describe genetic lesions. Screening FISH (5q-, -7, +8) from peripheral blood may be performed in case of less than 25 metaphases or dry tap.
Cytomorphology anaylsis of the bone marrow is the gold standard in the diagnostic field of MDS. There are no signs of dysplasia exclusively for MDS. A standardized approach of analysing bone marrow cells analyzing a variety of dysplastic features and the assessment of blasts is necessary. The major morphologic characteristics of specific MDS-subtypes like MDS are presented and explained in detail.