FIP1L1/PDGFRα fusion gene-negative chronic eosinophilic leukemia with t(5; 12)(q31;p13): a case report and review of literatures / 中华内科杂志

ABSTRACT

Objective To deepen the understanding of chronic eosinophilic leukemia (CEL).Methods The course of diagnosis and treatment in a case of FIP1L1/PDGFRα fusion gene negative CEL was reported. Flow cytometry was used to analyze the immunophenotype of the cells in peripheral blood and pleural fluid. Karyotype was analyzed with G-banding. The expression of FIP1L1/PDGFRα fusion gene was detected by RT-PCR technique. Routine pathological examination of the tissues from bone marrow, lung and spleen were performed. Result A sixteen-year-old girl had severe anemia, fever, splenomegaly,thrombocytopenia and dominant hypereosinophilia lasting for 22 months. Trephine biopsy showed a hypercellular marrow with eosinophilic proliferation and moderate reticular fibrosis. Eosinophilic infiltration was found in lung and spleen and embolism was also found in spleen. She had a clonal chromosomal abnormality t(5;12)(q31;p13). The expression of FIP1L1/PDGFRα was negative. An abnormal clone of T cells expressing CD3-,CD4-,CD8- was found in peripheral blood and pleural fluid, in which the cional T cell accounted for 5.43% and 1.66% of the total lymphocytes respectively. The patient was refractory to treatment with hydroxyurea, prednisone and interferon alpha. She had poor response to a combination of therapy with low dose cytosine arabinoside, mitoxantrone, vincristine, cyclophosphamide, methotrexate and prednisone. She did not respond to imatinib and died of multiple organ failure. Conclusion The present case fulfilled the WHO diagnostic criteria of FIP1L1/PDGFRα(-) CEL which did not respond to routine treatment and imatinib. Allogenic stem cell transplantation should be considered as early as possible in this case. It is noteworthy that clonal CD3-,CD4-,CD8- T-cell abnormality is related to the pathogenesis of CEL.