Study On The Morphology And The Clonal Origin Of Dysplastic Cells By Fluorescence In Situ Hybridization In Myelodysplastic Syndromes

Objective The clinical data and laboratory data of 28 patients with cytopenias, clonal cytogenetic abnormalities and unremarkable morphologic features were analyzed to determine the diagnosis of these patients; interphase FISH and morphologic analysis of bone marrow aspirates were performed to find the clonal origin of dysplatic cells in 9 MDSpatients.Methods1. part 1 Cytogenetic analysis of bone marrow cells was performed by direct method and /or 24h culture method .RHG banding was used for karyotype analysis;all BM aspirates were reviewed again to search for morphologic abnormalities;BM aspirates were followed–up in 7 patinents .2. part 2 Interphase FISH was performed with singal–color and dual-color DNA probes to investigate the clonal origin of dysplatic cells in 9 MDS patients.The statistic analysis was performed to testify the significance of variance between the proportions of dysplastic cells of the malignant clone and non-malignant clone. Result1. In part 1,all BM aspirates were found no dysplastic changes; 7 patients had a hematologic picture in accordance with aplastic anemia (AA), 21 had no remarkable morphologic features; remarkable dysplasia was found in 2 of them after 8 and 17 months later.2. Most of dysplastic cells in 8 of 9 MDS patients derived from neoplasia clone while 1 patient had a reverse result; some of non-dysplastic cells of all patients derived from malignant clone; in 8 patients, the proportion of dysplastic cells in malignant clone were significantly higher than that of non- malignant clone. Conclusion 1. 7 patients were diagnosed as AA with cytogenetic abnormalities while others as MDS without dysplastic changes; some of these patients would show clearly displastic findings in the development of the desease, so long time follow-up is necessary for these patients; in the development of MDS, cytogenetic abnormalities may be a early events than dysplastic morphologic changes. Cytogenetic abnormality itself may not be sufficient to lead to dysplasia.2. Most of dysplastic cells in MDS derived from malignant clone; some neoplasia clone could differentiate into mature cells; cytogenetic abnormalities may not be only factor lead to dysplasia, the occurrence of dysplasia in MDS may require cooperation of other factors.