Therapy-related myelodysplastic syndrome with der(17)t(12;17)(q13;p13) as a new recurrent cytogenetic abnormality after treatment for chronic lymphocytic leukemia.

A 54-year-old male presented to our hospital for evaluation of peripheral lymphocytosis. He was initially diagnosed with chronic lymphocytic leukemia (CLL) and treated with six cycles of fludarabine, cyclophosphamide, and rituximab chemotherapy. Therapy-related myelodysplastic syndrome (t-MDS) was suspected approximately 2 years later; in addition, complex karyotypic abnormalities including 5q deletion, monosomy 7, and der(17)t(12;17)(q13;p13) were found repeatedly in the patient's chromosome studies. The chromosomal abnormality der(17)t(12;17)(q13;p13) is very rare in hematologic malignancies, and has been reported in only two patients with therapy-related acute myeloid leukemia (t-AML). To our knowledge, this is the first report of t-MDS with der(17)t(12;17)(q13;p13) after treatment for CLL. In addition, we suggest that der(17)t(12;17)(q13;p13) should be considered a new recurrent, nonrandom chromosomal abnormality in patients with t-MDS/AML.