8p11 myeloproliferative syndrome: diagnostic challenges and pitfalls.

8p11 myeloproliferative syndrome (EMS) is a very rare clinicopathological entity which is characterized by the appearance of a myeloproliferative neoplasm in the bone marrow, peripheral lymphadenopathy, usually caused by T or B lymphoblastic lymphoma/leukemia, and a reciprocal translocation involving chromosome 8p11. Herein we describe a 22-year-old male patient with unusual clinical presentation of EMS. Namely, he initially presented with prolonged epistaxis. Complete blood count showed elevated hemoglobin (17.7g/dl), thrombocytopenia (98x109/l) and leukocytosis (57x109/l). Bone marrow aspirate and biopsy findings corresponded with the presence of a myeloproliferative neoplasm while cytogenetic analysis revealed t(8;13)(p11q12). After that ZMYM2-FGFR1 in-frame fusion was confirmed at the molecular level. Immediately after establishing the diagnosis of a myeloproliferative neoplasm (MPN) generalized lymphadenopathy was developed. Histopathologic examination of lymph node sample confirmed the diagnosis of a T cell lymphoblastic lymphoma without bone marrow involvement. Four cycles of Hyper CVAD chemotherapy were administered with complete morphological and cytogenetic remission. Four weeks after evaluation, patient developed peripheral blood monocytosis and eosinophilia without bone marrow criteria for acute leukemia. Cytogenetic analysis showed t(8;13) accompanied by complex numerical and structural aberrations. The patient underwent allogeneic stem cell transplantation (allo-SCT) from HLA matched sister and he subsequently achieved complete remission. In conclusion, patients with MPN and translocations involving chromosome 8 need to be carefully evaluated for EMS. However, having in mind the very aggressive clinical course of EMS allo-SCT is the only potential curative option.