Chronic myelogenous leukemia presenting in blast phase with nodal, bilineal myeloid sarcoma and T-lymphoblastic lymphoma in a child.

A 14-year-old boy presented with chronic myelogenous leukemia (CML) in blast phase with segregated extramedullary (nodal) myeloid sarcoma and T-lymphoblastic lymphoma. Immunohistochemical stains performed on the lymphadenectomy sample demonstrated T lymphoblasts in the lymph nodes and myeloblasts in the adjacent soft tissue. Fluorescence in situ hybridization performed on paraffin sections confirmed that both T-lymphoblast and myeloblast populations were positive for the t(9;22) BCR/ABL1 translocation. Subsequent flow cytometry analysis of the bone marrow showed expanded populations of abnormal myeloblasts and T lymphoblasts diagnostic of blast phase CML. To the best of our knowledge, bilineal blast phase of CML with segregated extramedullary T lymphoblasts and myeloblasts has not been reported.