Association study of GBA1 variants with MSA based on comprehensive sequence analysis -Pitfalls in short-read sequence analysis depending on the human reference genome.

Multiple system atrophy (MSA) is a neurodegenerative disorder characterized by various combinations of autonomic failure, parkinsonism, and cerebellar ataxia. To elucidate variants associated with MSA, we have been conducting short-read-based whole-genome sequence analysis. In the process of the association studies, we initially focused on GBA1, a previously proposed susceptibility gene for MSA, to evaluate whether GBA1 variants can be efficiently identified despite its extraordinarily high homology with its pseudogene, GBA1LP. To accomplish this, we conducted a short-read whole-genome sequence analysis with alignment to GRCh38 as well as Sanger sequence analysis and compared the results. We identified five variants with inconsistencies between the two pipelines, of which three variants (p.L483P, p.A495P-p.V499V, p.L483_M489delinsW) were the results of misalignment due to minor alleles in GBA1P1 registered in GRCh38. The miscalling events in these variants were resolved by alignment to GRCh37 as the reference genome, where the major alleles are registered. In addition, a structural variant was not properly identified either by short-read or by Sanger sequence analyses. Having accomplished correct variant calling, we identified three variants pathogenic for Gaucher disease (p.S310G, p.L483P, and p.L483_M489delinsW). Of these variants, the allele frequency of p.L483P (0.003) in the MSA cases was higher than that (0.0011) in controls. The meta-analysis incorporating a previous report demonstrated a significant association of p.L483P with MSA with an odds ratio of 2.92 (95% CI; 1.08 - 7.90, p = 0.0353).

Mucosa-associated lymphoid tissue lymphoma with t(11;18)(q21;q21) translocation: long-term follow-up results.

Translocation (11;18)(q21;q21) is found in mucosa-associated lymphoid tissue (MALT) lymphoma, resulting in API2/MALT1 gene fusion. It is known that t(11;18)-positive MALT lymphoma shows a tendency to disseminate and be resistant to Helicobacter pylori eradication by antibiotics. However, the prognostic features including recurrence and histological transformation (HT) remain unknown. We conducted a single-institute retrospective analysis of 464 patients with newly diagnosed MALT lymphoma, evaluating the impact of t(11;18) on clinical outcomes. One hundred and six patients were screened for the translocation by fluorescence in situ hybridization and/or reverse transcriptase-polymerase chain reaction. Of these patients, 26 patients (25%) were diagnosed as MALT lymphoma with t(11;18). The patients had a significantly shortened progression-free survival (PFS at 10 years; 26% v 57%; P = 0.004) compared to those without t(11;18). However, this did not translate into overall survival or incidence of HT. We confirmed previous reports stating that t(11;18)-positive MALT lymphoma showed disseminated disease and refractoriness to H. pylori eradication therapy. Patients with t(11;18) had more frequent monoclonal gammopathy, especially of IgM subtype (31% v 8%; P = 0.008), some of which developed class switch. These findings characterize the features of t(11;18)-positive MALT lymphoma, suggesting that it comprises a distinct clinical entity of MALT lymphoma.

Double-Expressor Lymphoma Is Associated with Poor Outcomes after Allogeneic Hematopoietic Cell Transplantation.

Double-expressor lymphoma (DEL) is a diffuse large B cell lymphoma that exhibits co-expression of MYC and BCL2 proteins by immunohistochemistry. Patients with double-expressor lymphoma have a poor prognosis after standard chemoimmunotherapy or after high-dose chemotherapy with autologous transplantation, but the prognostic impact of DEL after allogeneic hematopoietic cell transplantation has not been well characterized. We retrospectively analyzed 60 consecutive patients with de novo diffuse large B cell lymphoma or transformed follicular lymphoma who underwent allogeneic transplantation at our center and had available immunohistochemistry data. Thirty-seven patients (62%) had DEL. The 2-year progression-free and overall survival rates were lower in patients with DEL than in those without DEL (20% versus 78%; overall P <.001 and 46% versus 77%; overall P = .016, respectively). The cumulative incidence of disease progression at 2 years was higher in patients with DEL (60% versus 13%; overall P = .005). The cumulative incidence of nonrelapse mortality did not differ statistically in the 2 groups. Even in patients with DEL and chemosensitive disease at transplantation, the 2-year progression-free survival rate was only 27% due to early disease progression. Multivariate analysis showed associations between DEL and increased risks of progression-free survival events (hazard ratio [HR], 4.58; 95% confidence interval [CI], 2.07-10.2; P <.001), overall mortality (HR, 2.29; 95% CI, 1.03-5.09; P = .042) and disease progression (HR, 3.60; 95% CI, 1.38-9.44; P = .009). Patients with DEL had poor outcomes after allogeneic transplantation. Innovative strategies are needed to improve outcomes in this population.

Partial deletion of the ALK gene in ALK-positive anaplastic large cell lymphoma.

Anaplastic lymphoma kinase (ALK) protein is an orphan receptor tyrosine kinase that is constitutively activated by aberrant translocations of the ALK gene in anaplastic large cell lymphoma, ALK-positive and several other cancers. Additionally, aberrant mutation and amplification of the ALK gene, resulting in ALK kinase activation, were detected mainly in neuroblastoma. Recently, truncated ALK protein was also reported in neuroblastoma. Here, we describe a novel truncated form of the ALK transcript with in-frame skipping through exons 2 to 17 (ALKΔ2-17) in anaplastic large cell lymphoma, ALK-positive. The ALKΔ2-17 showed ligand-independent deregulated phosphorylation that initiated strong STAT3 signalling in NIH3T3 cells. The ALKΔ2-17-transduced NIH3T3 cells showed oncogenic potential in a colony formation assay. Our data indicate that the aberrant deletion of the ALK gene might be oncogenic, providing a novel insight into the oncogenic role of the ALK pathway.

Expression pattern of PD-L1 and PD-L2 in classical Hodgkin lymphoma, primary mediastinal large B-cell lymphoma, and gray zone lymphoma.

OBJECTIVES: We aimed at investigating the relationship between classical Hodgkin lymphoma (cHL), primary mediastinal large B-cell lymphoma (PMBL), and gray zone lymphoma (GZL) with intermediate characteristics between cHL and PMBL, from the perspective of the aberration in programed cell death 1 and the programed death ligands (PDLs) network. METHODS: We explored the expression levels of PDLs and chromosomal anomalies in 67 cases: 34 cases with cHL, 20 with PMBL, and 13 with GZL, using immunohistochemical analyses and Fluorescence In Situ Hybridization (FISH). RESULTS: Twenty-one cHL (62%), 3 PMBL (15%), and 6 GZL (46%) cases showed staining to PD-L1 antibodies in more than 70% of tumor cells. Two cHL (6%), 10 PMBL (50%), and 3 GZL (23%) cases were not stained by PD-L1 antibodies. Patients over 40 years old manifest more frequent expression of PD-L1 in cHL. Proportion of tumors stained by PD-L2 antibody was increased in PMBL. FISH analyses with a PD-L1/PD-L2 probe detected 5 amplification, 1 gain, and 7 polysomy cases in cHL, 1 amplification and 1 polysomy case in GZL, and amplification in 1 PMBL case. CONCLUSION: We identified increased staining of PD-L1 in cHL and that of PD-L2 in PMBL. GZL had a pattern similar to that of cHL.

Clinicopathological features of classical Hodgkin lymphoma in patients ≥ 40 years old, with special reference to composite cases.

OBJECTIVE: Classical Hodgkin lymphoma shows a peak incidence at 15-35 years, and a second peak in elderly patients; however, pathological characteristics of elderly patients with classical Hodgkin lymphoma have not been analyzed enough. METHODS: In a total of 154 patients with classical Hodgkin lymphoma, we analyzed the clinicopathological characteristics of classical Hodgkin lymphoma patients aged ≥ 40 years old, with special reference to the incidence, histopathology and outcome of patients with composite classical Hodgkin lymphoma. RESULTS: Of 154 patients with classical Hodgkin lymphoma, 50 (32%) were ≥ 40 years old. The 5-year progression-free and overall survival rates were 59 and 86%, respectively. Thirty-eight patients (76%) had non-composite classical Hodgkin lymphoma, 10 patients (20%) had composite (6 simultaneous and 4 consecutive) classical Hodgkin lymphoma and B-cell non-Hodgkin lymphoma and 2 patients (4%) had methotrexate-associated classical Hodgkin lymphoma. Of 10 patients with composite classical Hodgkin lymphoma, composite lymphomas were detected throughout the staging procedure of the upper gastrointestinal tract or bone marrow in 4 patients. Fluorescence in situ hybridization revealed that the composite lymphomas of 4, 1 and 5 patients were related, unrelated and of unknown correlation status, respectively. The treatments after the diagnosis of a classical Hodgkin lymphoma component varied, and three patients died of lymphoma. CONCLUSIONS: We found that the incidence of composite classical Hodgkin lymphoma in patients ≥ 40 years old was 20%. Correct diagnosis and optimal treatment for patients with composite classical Hodgkin lymphoma and B-cell non-Hodgkin lymphoma is highly important in this patient population.

Frequent inactivation of A20 in B-cell lymphomas.

A20 is a negative regulator of the NF-kappaB pathway and was initially identified as being rapidly induced after tumour-necrosis factor-alpha stimulation. It has a pivotal role in regulation of the immune response and prevents excessive activation of NF-kappaB in response to a variety of external stimuli; recent genetic studies have disclosed putative associations of polymorphic A20 (also called TNFAIP3) alleles with autoimmune disease risk. However, the involvement of A20 in the development of human cancers is unknown. Here we show, using a genome-wide analysis of genetic lesions in 238 B-cell lymphomas, that A20 is a common genetic target in B-lineage lymphomas. A20 is frequently inactivated by somatic mutations and/or deletions in mucosa-associated tissue lymphoma (18 out of 87; 21.8%) and Hodgkin's lymphoma of nodular sclerosis histology (5 out of 15; 33.3%), and, to a lesser extent, in other B-lineage lymphomas. When re-expressed in a lymphoma-derived cell line with no functional A20 alleles, wild-type A20, but not mutant A20, resulted in suppression of cell growth and induction of apoptosis, accompanied by downregulation of NF-kappaB activation. The A20-deficient cells stably generated tumours in immunodeficient mice, whereas the tumorigenicity was effectively suppressed by re-expression of A20. In A20-deficient cells, suppression of both cell growth and NF-kappaB activity due to re-expression of A20 depended, at least partly, on cell-surface-receptor signalling, including the tumour-necrosis factor receptor. Considering the physiological function of A20 in the negative modulation of NF-kappaB activation induced by multiple upstream stimuli, our findings indicate that uncontrolled signalling of NF-kappaB caused by loss of A20 function is involved in the pathogenesis of subsets of B-lineage lymphomas.

Whole-Exome Sequencing Revealed a Pathogenic Germline Variant in the Fumarate Hydratase Gene, Leading to the Diagnosis of Hereditary Leiomyomatosis and Renal Cell Cancer.

The diagnosis of hereditary skin tumors is difficult for "old" diagnostic tools such as immunohistochemistry. Whole-exome sequencing analysis as a "new" diagnostic tool enables us to make a final diagnosis in spite of unknown hereditary diseases in the past. Hereditary leiomyomatosis and renal cell cancer are autosomal dominant hereditary cancer syndromes characterized by uterine myomas, cutaneous leiomyomas, and aggressive renal cell cancer. The syndrome is associated with pathogenic germline variants in the fumarate hydratase gene. Herein, we demonstrate a pathogenic germline variant of the fumarate hydratase gene in a 60-year-old woman with multiple cutaneous leiomyomas, leading to the diagnosis of hereditary leiomyomatosis and renal cell cancer. Whole-exome sequencing analysis using genomic DNA extracted from peripheral blood leukocytes revealed one germline variant in the FH gene on chromosome 1 (c.290G>A, p.Gly97Asp). She received total hysterectomy due to uterine myoma, which strongly supported the diagnosis. No tumor was detected in her kidney by computed tomography and ultrasound examination. Genetic examination for the mutation of the fumarate hydratase gene is important in order to reach the correct diagnosis and to detect renal cancer at its early stage.

Ewing sarcoma arising after treatment of diffuse large B-cell lymphoma.

We report the case of a patient in whom the diagnosis of Ewing sarcoma arising from a soft tissue was made after successful treatment of diffuse large B-cell lymphoma. A 65-year-old woman presented with a rapidly growing mass in her left scapular region 8 years after successful chemotherapy with the cyclophosphamide, hydroxydaunomycin hydrochloride, vincristine, prednisolone regimen for diffuse large B-cell lymphoma. Computed tomographic examination and magnetic resonance imaging of the thorax revealed an intramuscular tumour measuring 40 mm in size in the left scapular region. Histopathological examination of an open biopsy specimen revealed a small round cell tumour that showed positive staining for CD99. Fluorescence in situ hybridization showed a split signal by a break-apart probe for the EWS gene in chromosome 22q12. Reverse transcriptase-polymerase chain reaction confirmed the expression of EWS-FLI1 fusion transcripts. Based on these findings, the patient was diagnosed as having secondary Ewing sarcoma. Despite adjuvant chemotherapy, however, she died of pulmonary metastases 2 years after the diagnosis of Ewing sarcoma. Therapy-related haematological malignancies with balanced translocations have been reported previously. A mechanism similar to that underlying the development of secondary malignancy might explain the occurrence of this solid cancer.

Deletion of the TNFAIP3/A20 gene detected by FICTION analysis in classical Hodgkin lymphoma.

BACKGROUND: The TNFAIP3 gene, which encodes a ubiquitin-modifying enzyme (A20) involved in the negative regulation of NF-κB signaling, is frequently inactivated by gene deletions/mutations in a variety of B-cell malignancies. However, the detection of this in primary Hodgkin lymphoma (HL) specimens is hampered by the scarcity of Hodgkin Reed-Sternberg (HR-S) cells even after enrichment by micro-dissection. METHODS: We used anti-CD30 immunofluorescence with fluorescence in-situ hybridization (FISH) to evaluate the relative number of TNFAIP3/CEP6 double-positive signals in CD30-positive cells. RESULTS: From a total of 47 primary classical Hodgkin lymphoma (cHL) specimens, 44 were evaluable. We found that the relative numbers of TNFAIP3/CD30 cells were distributed among three groups, corresponding to those having homozygous (11%), heterozygous (32%), and no (57%) deletions in TNFAIP3. This shows that TNFAIP3 deletions could be sensitively detected using our chosen methods. CONCLUSIONS: Comparing the results with mutation analysis, TNFAIP3 inactivation was shown to have escaped detection in many samples with homozygous deletions. This suggests that TNFAIP3 inactivation in primary cHL specimens might be more frequent than previously reported.

Clinicopathological analysis of primary refractory diffuse large B-cell lymphoma treated with rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisolone chemoimmunotherapy.

BACKGROUND: Approximately 15% of patients with diffuse large B-cell lymphoma (DLBCL) experience refractory or early relapsed disease after initial rituximab-containing chemoimmunotherapy is regarded as a primary refractory disease. Although the standard treatment for relapsed DLBCL is high-dose chemotherapy and autologous stem cell transplantation (HDC-ASCT), the efficacy of this approach for primary refractory DLBCL is not well understood. We aimed to investigate the clinicopathological characteristics and outcomes of patients with primary refractory DLBCL. METHODS: Sixty-nine consecutive patients with primary refractory DLBCL who were treated at our institution were categorized as partial responders (partial response to rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisolone [R-CHOP] or relapse within 6 months of R-CHOP) (n = 41) or primary progressors (no response to R-CHOP) (n = 28). Survival curves were constructed using the Kaplan-Meier method and compared using the log-rank test. RESULTS: At initial diagnosis, 70% of patients had Ann Arbor stage III/IV disease, 56% had non-germinal center B-cell-like type DLBCL, and 42% had double-expressor lymphoma (MYC and BCL2 expression). The 3-year overall survival rate was significantly poorer in the primary progressors group than in the partial responders' group (15% vs. 48%, p < 0.001). Four of 17 patients treated with HDC-ASCT were primary progressors; only one patient survived without relapse. Although double-expressor lymphoma status did not significantly impact overall survival among all patients (p = 0.794), it was identified as an independent poor prognostic factor in HDC-ASCT-treated patients (p = 0.002). CONCLUSIONS: We identified a subgroup of patients with primary refractory DLBCL who may not benefit from current treatment strategies. Further treatment development is needed to improve the outcomes of these patients.

Histological and immunophenotypic changes in 59 cases of B-cell non-Hodgkin's lymphoma after rituximab therapy.

Rituximab is a chimeric monoclonal antibody that recognizes the CD20 antigen. It has been used to treat B-cell non-Hodgkin lymphoma (B-NHL), but recently rituximab resistance has been a cause for concern. We examined histological and immunohistochemical changes in 59 patients with B-NHL after rituximab therapy. The patients comprised 32 men and 27 women with a median age of 59 years. Pre-rituximab specimens comprised 34 follicular lymphomas (FL), 11 diffuse large B-cell lymphomas (DLBCL), 10 mantle cell lymphomas, two marginal zone B-cell lymphomas (MZBCL), and two chronic lymphocytic leukemias (CLL). CD20 expression in lymphoma cells was evaluated by immunohistochemistry or flow cytometry. Post-rituximab materials were taken a median of 6 months (4 days to 59 months) after rituximab therapy. Sixteen cases (27%) showed loss of CD20 expression with four histological patterns: pattern 1, no remarkable histological change (FL, 5; DLBCL, 3; and CLL, 2); pattern 2, proliferation of plasmacytoid cells (FL, 2; DLBCL, 1; and MZBCL, 1); pattern 3, transformation to classical Hodgkin's lymphoma (FL, 1); and pattern 4, transformation to anaplastic large cell lymphoma-like undifferentiated lymphoma (FL, 1). Loss of CD20 was unrelated to the interval of biopsies, treatment regimen, clinical response, and frequency of rituximab administration. Loss of CD20 within 1 month of rituximab therapy (3/14, 21%) and regain of CD20 (2/7, 29%) were not frequent. CD20-positive relapse with transformation occurred most frequently in cases of early relapse. In conclusion, B-NHL showed various histological and immunophenotypic changes after rituximab therapy, including not only CD20 loss but also proliferation of plasmacytoid cells or transformation to special subtypes of lymphoma.

Identification of novel candidate loci for anorexia nervosa at 1q41 and 11q22 in Japanese by a genome-wide association analysis with microsatellite markers.

The Japanese Genetic Research Group for Eating Disorders (JGRED) is a multisite collaborative study group that was organized for the systematic recruitment of patients with an eating disorder for the purpose of genetic study in Japan. We conducted a genome-wide case-control association study using 23 465 highly polymorphic microsatellite (MS) markers to identify genomic loci related to anorexia nervosa (AN). Pooled DNA typing in two screening stages, followed by individual typing of 320 AN cases and 341 controls, allowed us to identify 10 MS markers to be associated with AN. To narrow down genomic regions responsible for the association of these MS markers, we further conducted a single-nucleotide polymorphism (SNP) association analysis for 7 of the 10 loci in 331 AN cases and 872 controls, which include the 320 AN cases and the 341 controls genotyped in the MS screening, respectively. Two loci, namely 1q41 and 11q22, remained significantly associated with AN in the SNP-based fine mapping, indicating the success in narrowing down susceptibility regions for AN. Neither of these loci showed a positive evidence of association with bulimia nervosa. The most significant association was observed at SNP rs2048332 (allelic P-value=0.00023) located at 3'-downstream of the SPATA17 gene on the 1q41 locus. The association analysis for MS-SNP haplotypes detected a statistically significant association (permutation P-value=0.00003) of the A-4-G-T haplotype that comprised four SNP/MS markers (rs6590474-D11S0268i-rs737582-rs7947224) on the 11q22 locus with AN. This linkage disequilibrium block spanning a 20.2-kb interval contains exon 9 of the CNTN5 gene encoding contactin 5.

Diffuse large B-cell lymphoma after transformation from low-grade follicular lymphoma: morphological, immunohistochemical, and FISH analyses.

Follicular lymphoma (FL) is one of the most common subtypes of non-Hodgkin lymphoma and frequently transforms to diffuse large B-cell lymphoma (DLBCL). To clarify some aspects of the natural history of FL, we retrospectively examined 43 consecutive patients who had DLBCL with pre- or coexisting FL grade 1 or 2. The patients comprised 22 men and 21 women with a median age of 53 years. Most of the patients (34/43) showed advanced-stage (III or IV) disease initially. We examined both FL and DLBCL components morphologically, immunohistochemically, and by interface fluorescence in situ hybridization (FISH: IGH/BCL2 fusion, BCL6 translocation) analysis. Most of the DLBCLs were classified as the centroblastic subtype, with two exceptions of the anaplastic subtype. Immunohistochemical analysis of both the FL and DLBCL components revealed the following respective positivity rates: CD20 100%/100%, CD10 86%/66%, Bcl-2 96%/91%, Bcl-6 84%/88%, MUM1 16%/34%, CD30 0%/20%, CD138 0%/0%, and CD5 0%/3%. Loss of CD10 (6/36, 17%) and gain of MUM1 (7/28, 25%) and CD30 (5/21, 24%) through transformation were not infrequent. High positivity rates for Bcl-2 and Bcl-6 were maintained throughout transformation. Among the DLBCLs, 84% were classified as the germinal center B-cell phenotype (GCB) and 16% as non-GCB in accordance with the criteria of Hans et al. IGH/BCL2 fusion was detected by FISH in 89% of FLs and 82% of DLBCLs. BCL6 translocation was detected in 1/6 (17%) DLBCLs without IGH/BCL2 fusion. Thus, although the morphological features and FISH results for DLBCL were consistent with transformed FL, the immunophenotype showed wide heterogeneity.

Follicular lymphoma of the duodenum: a clinicopathologic analysis of 26 cases.

OBJECTIVE: Follicular lymphomas (FLs) occur commonly in the lymph nodes, and duodenal FL (DFL) is reported to be rare. METHODS: We analysed the clinical, morphological, immunohistochemical and genetic features of 26 cases of DFL. Primary DFLs and systemic FLs that involved the duodenum at any point during the clinical course were included in the analysis. RESULTS: Typically, primary DFLs (14 cases) were found incidentally at routine medical check-ups, whereas involvement of the duodenum by systemic FLs (12 cases) was found through staging procedures. All cases involved the second portion of the duodenum. Helicobacter pylori infection was common (71%). In all cases, the histologic grade was low (either grade 1 or 2), and CD20, CD10 and Bcl-2 were positive by immunohistochemistry. Immunoglobulin heavy chain gene (IGH) and bcl-2 gene (BCL2) fusion was frequently shown by fluorescence in situ hybridization (FISH) analysis: nine of 12 cases (75%) of primary DFL and 10 of 12 cases (83%) of systemic DFL were positive. Treatment regimens employed were rituximab (R) plus chemotherapy (10), R (6), chemotherapy (3), irradiation (3) and the other three patients were subjected to observation. After a median follow-up duration of 40 months (ranging 11-96 months), 17 patients were alive without disease, seven were alive with disease and one had died of lymphoma. CONCLUSIONS: Primary DFLs resemble systemic and nodal FLs, except that the former has high incidence of early stage and low-grade histology. The duodenum appears to be a frequently involved extranodal site of FL with IGH/BCL2.

Gene Expression Profile Signature of Aggressive Waldenström Macroglobulinemia with Chromosome 6q Deletion.

BACKGROUND: Waldenström macroglobulinemia (WM) is a rare, indolent B-cell lymphoma. Clinically, chromosome 6q deletion (6q del) including loss of the B lymphocyte-induced maturation protein 1 gene (BLIMP-1) is reported to be associated with poor prognosis. However, it remains unclear how the underlying biological mechanism contributes to the aggressiveness of WM with 6q del. METHODS: Here, we conducted oligonucleotide microarray analysis to clarify the differences in gene expression between WM with and without 6q del. Gene ontology (GO) analysis was performed to identify the main pathways underlying differences in gene expression. Eight bone marrow formalin-fixed paraffin-embedded samples of WM were processed for interphase fluorescence in situ hybridization analysis, and three were shown to have 6q del. RESULTS: GO analysis revealed significant terms including "lymphocyte activation" (corrected p value=6.68E-11), which included 31 probes. Moreover, IL21R and JAK3 expression upregulation and activation of the B-cell receptor signaling (BCR) pathway including CD79a, SYK, BLNK, PLCγ2, and CARD11 were detected in WM with 6q del compared with WM without 6q del. CONCLUSION: The present study suggested that the BCR signaling pathway and IL21R expression are activated in WM with 6q del. Moreover, FOXP1 and CBLB appear to act as positive regulators of the BCR signaling pathway. These findings might be attributed to the aggressiveness of the WM with 6q del expression signature.

Clinicopathological prognostic factors of 24 patients with B-cell lymphoma, unclassifiable, with features intermediate between diffuse large B-cell lymphoma and Burkitt lymphoma.

B-cell lymphoma, unclassifiable, with features intermediate between diffuse large B-cell lymphoma and Burkitt lymphoma (iBL/DLBCL), is a rare, but an aggressive subtype. In iBL/DLBCL, clinicopathological prognostic factors, including MYC and BCL2 translocations (double hit translocation, DHT) and the expression of both MYC and BCL2 (double hit score 2, DHS2), have not been studied thoroughly. We retrospectively analyzed the prognostic impact of clinicopathological factors, including MYC split, IGH/BCL2 fusion, MYC and BCL2 expressions, in 24 iBL/DLBCL patients (median age: 47 years). Fifteen patients (62 %) underwent intensive chemotherapy, and nine patients (38 %) underwent rituximab-cyclophosphamide, doxorubicin, vincristine, and prednisolone (R-CHOP). The 5-year progression-free (PFS) and overall survival (OS) rates of intensive chemotherapy and R-CHOP were 57 and 72 %, respectively. PFS was significantly shorter in patients with high IPI score (P < .0001), stage IV (P = .001), aged ≥60 years (P = .042), IGH/BCL2 fusion (P = .029), DHS2 (P = .015), and DHT (P = .03). OS was significantly shorter in patients with high IPI score (P < .0001) and aged ≥60 years (P = .008). In iBL/DLBCL, IGH/BCL2 fusion, DHS2, and DHT were pathological prognostic factors for poor PFS, while IPI remained as more predictive for PFS and OS.

FUS-ERG gene fusion in isolated myeloid sarcoma showing uncommon clinical features.

FUS-ERG gene fusion has not been reported in cases of myeloid sarcoma (MS), a subtype of acute myeloid leukemia involving extramedullary anatomic sites. Here, we report a case of a 48-year-old man with primary isolated MS of the anterior mediastinum, who later developed multiple extramedullary recurrences without bone marrow infiltration throughout the course. G-banding analysis of the cells in pericardial effusion at recurrence showed complex karyotypic abnormalities including t(16;21)(p11.2;q22). FUS break-apart fluorescent in situ hybridization analysis showed split signals in biopsy sections at initial diagnosis and recurrence. Reverse transcriptase polymerase chain reaction and direct sequencing demonstrated the presence of the FUS-ERG chimeric gene transcript. The patient underwent cord blood transplantation, but died of pneumonia on day 64. To our knowledge, this is the first report of isolated MS carrying FUS-ERG gene fusion. In future study, relationship between the fusion gene and uncommon clinical features should be investigated in isolated MS.