Issues in the pathology and diagnosis of the chronic myeloproliferative disorders and the myelodysplastic syndromes.

We have attempted to discuss some of the issues that interest pathologists who are involved in the diagnosis of CMPD and MDS. In most cases, correlation of the clinical findings with the findings in the blood and marrow will allow the morphologist to arrive at a proper diagnosis. Nevertheless, there will continue to be cases that are difficult to classify, or in which the clinical features are out of keeping with the morphologic features. These cases are challenging and thought-provoking, and the application of newer diagnostic techniques, such as molecular genetics, may provide important insights.