[Clinical pathological features of the 8p11 myeloproliferative syndrome]

This study was aimed to investigate the clinico-pathological features, diagnosis and treatment of the 8p11 (eight p11) myeloproliferative syndrome (EMS). Morphological changes of cells were evaluated by bone marrow smear and biopsy. The cell immunophenotypes were analysed by flow cytometry. Karyotypes were determined by conventional cytogenetic method, and bcr/abl fusion gene was detected by reverse transcription-polymerase chain reaction (RT-PCR). The results indicated that EMS was a relatively rare disease characterized by the occurrence of a bcr/abl-negative myeloproliferative disorder and a T-cell lymphoblastic lymphoma (T-LBL). Bone marrow examination showed myeloid hyperplasia or myeloproliferative neoplasm, often accompanied by eosinophilia. Flow cytometric immunophenotyping showed increased myelomonoblasts; cytogenetic analysis showed a translocation at the 8p11 locus; RT-PCR demonstrated non bcr/abl fusion gene. At the molecular level, all cases carried a chromosomal abnormality involving the fibroblast growth factor receptor 1 (FGFR1) at chromosome 8p11. Up to now, 11 partner genes have been identified and associated with FGFR1 rearrangements. The most common partner is ZNF198 on chromosome 13q11-12. Majority of patients terminate in acute myeloid leukemia which is resistant to conventional chemotherapy. Currently, the only curative option appears to be allogeneic hematopoietic stem cell transplantation. In conclusion, EMS is myeloid and lymphoid neoplasm, associates with FGFR1 rearrangements. It is usually misdiagnosed as T-LBL, atypical chronic myeloid leukemia (aCML) or chronic myelogenous-monocytic leukemia (CMML). Timely cytogenetic and molecular biological examination is vital in order to avoid misdiagnosis and mistreatment.