OBJECTIVE: To investigate the clinical application of fluorescent in situ 
hybridization (FISH) for the differential diagnosis of myelodysplastic syndromes 
(MDS) and aplastic anemia (AA).
METHODS: A FISH kit capable of detecting the chromosomal abnormalities related 
to MDS was used to analyze 94 patients who were suspected to have AA by bone 
marrow morphology.
RESULTS: Cytogenetic abnormalities were detected in 11 of the 94 patients, which 
included trisomy 8 (5 cases), 20q- (1 case) and -Y (1 case). There were 4 cases 
related to MDS, which included 3 cases of 5q-, in which 1 case carry 20q- at the 
same time, and 7q- (1 case). No significant difference was found between the MDS 
and AA groups in terms of age, sex or routine blood examination including 
absolute neutrophil count, hemoglobin content and platelet count.
CONCLUSION: FISH can detect certain cytogenetic abnormalities related to MDS in 
patients morphologically diagnosed as AA.