Myelodysplastic syndromes (MDS) represent a group of clonal hematological malignancies characterized by
ineffective hematopoiesis. Other hematological disorders associating dysplastic features are grouped under the
myelodysplastic/ myeloproliferative neoplasms (MDS/MPN) category. The great diversity of the acquired chromosomal
abnormalities described in MDS highlights the molecular heterogeneity of these diseases. We report on 12 MDS and 3
MDS/MPN patients investigated by cytogenetic and molecular techniques (FISH). The most frequent chromosomal
anomalies were 5q deletion and trisomy 8. Other trisomies, deletions and new translocations were also detected. MDS
and MDS/MPN stand as challenging entities in hemato-oncology due to their heterogeneity. Thus, genetic testing
provides important means for diagnosis confirmation and offers further insight into the prognosis and management of
these patients