Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukemia (ALL) may include the lymphoid blast crisis of chronic myeloid leukemia (CML-BC). We applied fluorescence in situ hybridization (FISH) of the BCR-ABL fusion gene to peripheral blood and/or bone marrow smears to determine whether the fusion was restricted to mononuclear cell nuclei or if segmented cell nuclei representing mature neutrophils also carried the fusion (Seg-FISH). Among 20 patients with Ph+ ALL without a prior diagnosis of CML, 9 were Seg-FISH+ and 11 were Seg-FISH-. Seg-FISH+ cases were characterized by a higher rate of p210-type BCR-ABL transcripts, higher white cell and blast counts, and a higher rate of myeloid and T-lymphoid antigen expression than Seg-FISH- cases, in addition to ‘major route' cytogenetic abnormalities associated with CML-BC. Eighteen patients were treated with tyrosine kinase inhibitors (TKIs) either alone or in combination with multiagent chemotherapy, and 7 underwent allogeneic hematopoietic stem cell transplantation. Progression-free and overall survivals were greater in the Seg-FISH+ group than in the Seg-FISH- group. These results suggest that the Seg-FISH+ group represents lymphoid CML-BC that occurs de novo, while the Seg-FISH- represents Ph+ ALL in the strict sense, and the two groups are associated with survival when treated with TKIs or TKI-combined therapy.

We describe the establishment and characterization of a cell line, AM-HLH, obtained from a patient with Epstein-Barr virus-positive (EBV ) nodular sclerosis-type Hodgkin lymphoma (HL). The cells were positive for CD2 and CD30 and negative for CD15. The immunoglobulin heavy- and κ light-chain genes were rearranged. The karyotype was of the triploid range. Southern blotting using the EBV terminal repeat probe detected 3 hybridizing bands that were identical to those of the parental HL material. The cells expressed EBV-encoded RNAs as well as latent genes (EBNA1, EBNA2, LMP1, and LMP2A) and lytic genes (BZLF1 and BALF2). Fluorescence in situ hybridization (FISH) with the cosmid pJB8 clone containing a fragment of EBV DNA as a probe revealed multiple hybridization signals at a marker chromosome. Additional FISH using whole chromosome painting and centromere probes in combination with multicolor FISH determined that multiple EBV copies were clustered within the chromosome 20 materials of the marker chromosome. Culture supernatants of AM-HLH contained IL-10 as measured by the bead-based immunoassay. It is possible that an integrated EBV genome and cellular genes on chromosome 20 were coamplified, leading to the enhanced expression of genes involved in cell growth control. The AM-HLH cell line will be useful to clarify the role of cytokines in the development of EBV HL.

We described four patients with diffuse large B‐cell lymphoma (DLBCL) carrying t(9;14)(p13;q32) that places the PAX5 adjacent to the immunoglobulin heavy chain (IGH) gene. Ages ranged between 63 and 80, and three were female. One developed a nodal disease, and the other three involved extranodal organs. The lymphoma cells were CD10−/BCL6−/MUM1+ in three and CD10+/BCL6+/MUM1+ in one. BCL2 was weak or negative. All had t(9;14)(p13;q32), and three had additional 14q32/IGH translocations or +der(14)t(9;14)(p13;q32). Fluorescence in situ hybridization using the PAX5 break‐apart probe showed that the locus was disrupted between the 5′ and 3′ probes or within the 5′ probe. Immunohistochemistry (IHC) using a monoclonal antibody against PAX5 showed strong nuclear positivity in all four patients. Cell block IHC of a CD30+ DLBCL cell line, KIS‐1, which carried the t(9;14)(p13;q32) and PAX5‐IGH fusion gene, reproduced the CD10−/BCL6−/MUM1+ immunophenotype, low‐level BCL2, and strong nuclear PAX5. Uniform nuclear positivity of MUM1 in all four cases and KIS‐1 cells suggest that these lymphomas arose at a late stage of B‐cell differentiation, where expression of PAX5 physiologically becomes downregulated. It is therefore possible that high‐level PAX5 resulting from t(9;14)(p13;q32) at this stage of differentiation perturbs the plasma cell differentiation program initiated by PAX5 repression, thereby contributing to the development of a fraction of DLBCL.

We describe 10 cases of diffuse large B-cell lymphoma (DLBCL) confined to the bone marrow (BM), spleen, and liver, as evidenced by the uniformly increased uptake of fluorodeoxyglucose (FDG) on positron emission tomography combined with computed tomography (PET/CT). Ages ranged from 56 to 87. All, but one patient presented with 'B' symptoms, a poor performance status, and hepatosplenomegaly. All patients showed cytopenia and elevated lactate dehydrogenase levels and were classified into the high-risk category of the International Prognostic Index scoring. BM infiltration was diffuse, interstitial/intrasinusoidal, or mixed, and all showed the nongerminal center B immunophenotype. Five patients had a rearrangement involving 3q27/BCL6, while six had increased copies of MYC, BCL2, or BCL6. All patients were initially treated with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone, leading to complete responses in six out of eight evaluable patients. We propose BM, spleen, and liver-type DLBCL, which is defined by the findings of FDG-PET/CT.

Clinical, histopathological, and molecular features of mucosa-associated lymphoid tissue (MALT) lymphoma carrying the t(X;14) (p11;q32)/ GPR34-immunoglobulin heavy chain gene