A breast cancer patient with myelodysplastic syndrome postoperatively treated by radiation and tamoxifen administration--a case report.

A 72-year-old female developed pancytopenia 4 years after breast cancer surgery. She had received regional radiation postoperatively, and tamoxifen for 4 years. Bone marrow examination demonstrated immature myeloblasts and dysplastic cells. Myelodysplastic syndrome (MDS) of refractory anemia with excess blasts (RAEB) was diagnosed, and the patient died of cerebral hemorrhage 4 months after the diagnosis of RAEB. Radiation and the administration of tamoxifen were suspected to have played a role in the development of secondary MDS.