Myelodysplastic syndrome appearing during imatinib mesylate therapy in a patient with GIST.

The introduction of imatinib has been a major advance in the treatment of gastrointestinal stromal tumor (GIST). However, despite its remarkable efficacy and toxicity profile little is known about the potential for long-term toxicity. This may be an important issue because some patients (pts) with chronic myelogenous leukemia (CML) develop, during imatinib treatment, chromosomal abnormalities in philadelphia chromosome (Ph) negative cells with evolution to myelodysplastic syndromes (MDS) or acute myeloid leukemia (AML), furthermore a nonrandom association between GIST and myeloid leukemia has been recently reported. We report here a case of refractory cytopenia with mutilineage dysplasia (RAEB-1) with monosomy 7 which rapidly transformed into AML in a patient with GIST during imatinib treatment.