The purpose of this study is to collect clinical and laboratory data for patients affected by intermediate 1 and low risk Myelodysplastic Syndrome (MDS) associated by deletion 5q who were prescribed Revlimid from 31October 2008 to present. Revlimid is available in Italy for these patients since October 2008 based on a local disposition of the Italian Drug Agency (AIFA) issued according to a National law named 648/96.