A Novel Fusion Partner in a Case of Myeloid/Lymphoid Neoplasm with FGFR1 Rearrangement

Abstract Introduction/Objective Myeloid/lymphoid neoplasms with rearrangement of FGFR1 are uncommon and heterogeneous group hematological malignancies that may present as myeloproliferative neoplasm, acute myeloid leukemia, T or B lymphoblastic lymphoma/leukemia, mixed phenotypic leukemia. Patients can lymphadenopathy, mediastinal mass, systemic symptoms. Eosinophilia is common in peripheral blood bone marrow. Several chromosomal rearrangements fusion genes have been described all them encode an aberrant tyrosine kinase. Tyrosine kinase inhibitors offer a prospective therapeutic approach although specific targeted therapies yet to be established. Methods/Case Report We case 14-year-old male who presented rapid neck pain swelling. Imaging revealed 15 x 8 6 cm mass extending into the anterior mediastinum. Laboratory evaluation anemia, thrombocytopenia, leukocytosis (41.7 K/mm3), absolute eosinophilia blasts 50%. Flow cytometry demonstrated population T-lymphoblasts comprising about 60% cellularity dim CD45, cytoplasmic CD3, CD7, TdT, CD38, CD4, CD5, CD10, CD15, supporting T-lymphoblastic leukemia/lymphoma. The patient received induction chemotherapy, subsequent marrow biopsy showed morphologic remission. Six weeks from diagnosis, developed gluteal atypical T-cell infiltrate was negative for TdT; at enlarging abdominal also TdT CD1a. At time molecular diagnostic studies wall discovered previously unpublished ATG16L1-FGFR1 fusion, myeloid/lymphoid neoplasm rearrangement, Results (if Case Study enter NA) NA. Conclusion Although variety translocations identified novel partner ATG16L1 has not reported. illustrates unusual extramedullary recurrence leukemia/lymphoma significant antigenic shift including loss