A Case of B-cell Lymphoma, Unclassifiable, with Features Intermediate between Diffuse Large B-cell Lymphoma and Burkitt Lymphoma in a Korean Child

B-cell lymphoma, unclassifiable, with features intermediate between diffuse large B-cell lymphoma (DLBCL) and Burkitt lymphoma (BL) (intermediate DLBCL/BL), is a heterogeneous group with some features resembling DLBCL and others resembling BL. Here, we report a case of intermediate DLBCL/BL in a Korean child. A 2-yr-old male was admitted for evaluation and management of left hip pain. Immunohistochemistry of a biopsy of the femur neck revealed tumor cells positive for CD20, CD10, BCL2, BCL6, and Ki67. A bone marrow (BM) aspirate smear revealed that 49.3% of all nucleated cells were abnormal lymphoid cells, composed of large- and medium-sized cells. Immunophenotyping of the neoplastic cells revealed positivity for CD19, CD10, CD20, and sIg lambda and negativity for CD34, Tdt, and myeloperoxidase (MPO). Cytogenetic and FISH analyses showed a complex karyotype, including t(8;14)(q24.1;q32) and IGH-MYC fusion. Intensive chemotherapy was initiated, including prednisone, vincristine, L-asparaginase, daunorubicin, and central nervous system prophylaxis with intrathecal methotrexate (MTX) and cytarabine. One month after the initial diagnosis, BM examination revealed the persistent of abnormal lymphoid cells; cerebrospinal fluid cytology, including cytospin, showed atypical lymphoid cells. The patient was treated again with cyclophosphamide, vincristine, prednisone, adriamycin, MTX, and intrathecal MTX and cytarabine. The patient died of sepsis 5 months after the second round of chemotherapy.