Isochromosome 17q as a sole anomaly: a distinct myelodysplastic syndrome entity?

We report four patients with myelodysplastic syndrome (MDS) with isochromosome i(17q) as the sole chromosomal anomaly. One patient was classified as refractory anemia (RA) and three as refractory anemia with excess of blasts (RAEB). All four patients shared several features such as male sex, advanced age, severe anemia, as well as a bone marrow with myeloproliferative characteristics: hypercellularity, prominent baso- and eosinophilia, and marked increase of micromegakaryocytes. We suggest that patients with i(17q) as the sole chromosomal anomaly may identify a distinct MDS with characteristics between MDS and chronic myeloproliferative disorders (CMPD).