Myeloproliferative disorder with profound hypereosinophilia associated with chemotherapy for breast cancer.

A 47-year-old woman developed a unique myeloproliferative disorder 36 months after receiving adjuvant chemotherapy postoperatively for breast carcinoma. Her bone marrow and peripheral blood exhibited many of the myelodysplastic changes commonly observed in treatment-linked leukemia. In addition, there was striking marrow and blood eosinophilia and eosinophilic infiltration in multiple organs. She also developed a poorly differentiated lymphocytic lymphoma which responded to therapy. Her myeloproliferative disorder, with marked eosinophilia, continued to progress, however, and she died shortly after its diagnosis.