8p11 Myeloproliferative Syndrome with t(7;8) Translocation Presenting as Acute Myeloid Leukemia: A Case Report and Literature Review

pnea upon exertion and also dizziness. The patient denied having any preexisting medical conditions. The initial laboratory results revealed a white blood cell (WBC) count of 22.6 × 10 9 /l with 7% blasts in the peripheral blood. Hemoglobin was 8.3 g/dl and platelet count was 80 × 10 9 /l. The initial bone marrow (BM) was hypercellular marrow with 93.6% blasts. Eosinophilia was not evident in either the peripheral blood or BM. The blasts expressed CD19, CD34, CD13, CD33 and CD11c. The conventional karyotyping showed 47,XX,+21[8]/46,XX,del(?9)(q10),i(9) (q10)[7]/46,XX[5] ( fig. 1 a, b). Fluorescence in situ hybridization (FISH) for PML-RARA , CBFB and KMT2A ( MLL ) were all negative. FISH for RUNX1T1-RUNX1 ( ETO-AML1 ) revealed 3 copies of the AML1 gene in 80% of the blasts. The others were all negative. Under the diagnosis of AML with trisomy 21, the patient received induction chemotherapy with cytarabine and idarubicin. Complete remission was confirmed by a follow-up BM examination on day 26; the blast count was down to 0.3% with a normal karyotype. She subsequently underwent 3 cycles of cytarabine-based consolidation from January to April 2011. A final BM exam was performed in June 2011, showing maintained remission, with a blast count of 0.3% and a normal karyotype. The 8p11 myeloproliferative syndrome (EMS) is a rare yet aggressive disorder molecularly characterized by disruption of the fibroblast growth factor receptor (FGFR1) gene [1] . Clinically, EMS manifests as diverse forms of hematologic malignancies, ranging from myeloproliferative neoplasm to mixed phenotype acute leukemia [2] . The 2008 World Health Organization revision designated EMS to a new category of ‘myeloid and lymphoid neoplasms associated with FGFR1 abnormalities’ [3] . Several partner genes that foster FGFR1 dimerization and activation have been reported, each fusing at 8p11: ZNF198 (13q12), CEP110 (9q33), LRRFIP1 (2q37), FGFR1OP (6q27), TIF1 (7q34), CUX1 (7q22), 11p15, FGFR1OP2 (12p11), CPSF6 (12q15), MYO18A (17q11), 17q25, HERVK (19q13) and BCR (22q11) [4] . Here, we describe an unusual case of a patient with long-standing EMS with t(7; 8), initially diagnosed as acute myeloid leukemia (AML) with trisomy 21, who achieved sustainable molecular and cytogenetic remission with conventional chemotherapy. This is the third reported case of EMS with t(7; 8) translocation worldwide and the first in Korea. In December 2010, a 32-year-old Korean female was admitted to the Seoul National University Bundang Hospital presenting with a 2-week history of worsening dysReceived: November 10, 2015 Accepted after revision: February 7, 2016 Published online: May 18, 2016