DIAGNOSIS, CLASSIFICATION, AND CYTOGENETICS OF MYELODYSPLASTIC SYNDROMES

Background and Objective. The diagnosis of myelodysplastic syndromes ( MDS) is essentially morphological and based on the presence of dysplas tic features in the peripheral blood and bone marrow. The French-Ameri can-British (FAB) Cooperative Group proposed a classification based on easily obtainable laboratory information. In spite of some limitation s, the FAB criteria have been useful for a long time. Currently, the r ecognition of other distinct morphological MDS subgroups such as hypoc ellular MDS and MDS with myelofibrosis, the increasing incidence of MD S in children as well as that of therapy-related MDS, and the finding of specific chromosomal alterations associated with different morpholo gical features, reveal the insufficiency of this classification. The a im of the present review is to examine some new aspects of the diagnos is, classification, and cytogenetics of MDS. Evidence and Information Sources. The authors of this review have been actively working and con tributing original papers on MDS for the last 15 years. They also orga nized or participated in the Fourth International Symposium on MDS (Ba rcelona, April 24-27, 1997). In addition, the present review criticall y examines relevant articles and abstracts published in journals cover ed by the Science Citation Index(C) and Medline(C). State of the Art a nd Perspectives. Most of investigators working on MDS tend to integrat e morphology and cytogenetics in the diagnosis and classification of t hese disorders. FAB criteria remain useful particularly for patients w ith not available cytogenetic study. Refractory cytopenia with multili neage dysplasia should be considered as a new MDS subtype. Some author s propose considering all patients with more than 20% of blast cells i n peripheral blood or bone marrow as having acute leukemia. Chronic my elomonocytic leukemia with myeloproliferative features may be included among chronic myeloproliferative disorders. MDS with myelofibrosis is recognized as a new MDS subtype. Therapy-related MDS (t-MDS) should b e classified according to the involved agents. Finally, besides includ ing chromo somal abnormalities in the diagnosis (e.g., RAEB with triso my 8), several cytogenetic abnormalities such as deletion 5q and delet ion 17p, associated to specific clinical-morphological features, shoul d be of help to identify new MDS syndromes. (C) 1998 Ferrata Storti Fo undation.