Misdiagnosis analysis of 2291 cases of haematolymphoid neoplasms.

Objective: To retrospectively analyze the reasons for misdiagnosis of haematolymphoid neoplasms and provide experience for improving the diagnostic level in China. Methods: A retrospective analysis was performed on 2291 cases of haematolymphoid diseases evaluated by the Department of Pathology of our hospital from 1 July 2019 to 30 June 2021. All 2291 cases were reviewed by two hematopathologist experts and classified according to the 2017 revised WHO classification criteria, supplemented immunohistochemistry (IHC), molecular biology and genetic information as needed. The diagnostic discordance between primary and expert review was evaluated. The possible causes of the diagnostic discrepancies were analyzed for each step involved in the procedure of diagnosis. Results: In total, 912 cases did not conform to the expert diagnoses among all the 2291 cases, with a total misdiagnosis rate of 39.8%. Among them, misdiagnosis between benign and malignant lesions accounted for 24.3% (222/912), misdiagnosis between haematolymphoid neoplasms and non-haematolymphoid neoplasms accounted for 3.3% (30/912), misdiagnosis among lineages accounted for 9.3% (85/912), misclassification in lymphoma subtypes accounted for 60.8% (554/912), and other misdiagnoses among benign lesions accounted for 2.3% (21/912) of cases, among which misclassification of lymphoma subtypes was the most common. Conclusion: The accurate diagnosis of haematolymphoid neoplasms is challenging, involving various types of misdiagnosis and complicated causes, however, it is important for precise treatment. Through this analysis, we aimed to highlight the importance of accurate diagnosis, avoid diagnostic pitfalls and to improve the diagnostic level in our country.

The PI3K/AKT/mTOR signaling pathway is aberrantly activated in primary central nervous system lymphoma and correlated with a poor prognosis.

BACKGROUND: Primary central nervous system lymphoma (PCNSL) is a specific subtype of non-Hodgkin lymphoma that is highly invasive and confined to the central nervous system (CNS). The vast majority of PCNSLs are diffuse large B-cell lymphomas (DLBCLs). PCNSL is a highly heterogeneous disease, and its pathogenesis has not yet been fully elucidated. Further studies are needed to guide individualized therapy and improve the prognosis. METHODS: In this study, we detected 1) the expression of p-AKT, p-mTOR, p-S6 and p-4E-BP1 by immunohistochemistry (IHC) and Western blotting, 2) the mRNA expression by real-time qPCR and 3) the deletion of PTEN gene by immunofluorescence in situ hybridization (FISH) in order to investigate the activation status of the PI3K/AKT/mTOR signaling pathway in PCNSL. Samples of reactive hyperplasia lymphnods were used as the control group. The correlations between the clinical characteristics and prognosis of PCNSL patients and the expression of p-AKT, p-mTOR, p-S6 and p-4E-BP1 and the deletion of PTEN were assessed. RESULTS: The IHC results showed that the positive expression rates of p-AKT, p-mTOR, p-S6 and p-4E-BP1 in PCNSL were significantly higher in the PCNSL group than in the control group (P < 0.05). The relative mRNA expression level of MTOR in PCNSL samples was significantly increased (P = 0.013). Correlation analysis revealed that the expression of p-mTOR was correlated with that of p-AKT, p-S6, p-4E-BP1. PTEN deletion was found in 18.9% of PCNSL samples and was correlated with the expression of p-AKT (P = 0.031). Correlation analysis revealed that the PCNSL relapse rate in the p-mTOR-positive group was 64.5%, significantly higher than that in the negative group (P = 0.001). Kaplan-Meier survival analysis showed inferior progression-free survival (PFS) in the p-mTOR- and p-S6-positive groups (P = 0.002 and 0.009, respectively), and PTEN deletion tended to be related to shorter overall survival (OS) (P = 0.072). Cox regression analysis revealed p-mTOR expression as an independent prognostic factor for a shorter PFS (hazard ratio (HR) =7.849, P = 0.046). CONCLUSIONS: Our results suggest that the PI3K/AKT/mTOR signaling pathway is aberrantly activated in PCNSL and associated with a poor prognosis, which might indicate new therapeutic targets and prognostic factors.

Sequential different B-cell antigen-targeted CAR T-cell therapy for pediatric refractory/relapsed Burkitt lymphoma.

Single antigen-targeted chimeric antigen receptor (CAR) T-cell therapy may be insufficient to induce a durable response in pediatric aggressive B-cell lymphomas. This clinical trial examined the feasibility of sequential different B-cell antigen-targeted CAR T-cell therapy for pediatric relapsed/refractory (R/R) Burkitt lymphoma. Twenty-three patients received the first CD19 CAR T-cell infusion. The patients who did not achieve an ongoing complete response (CR) underwent 1 or more sequential infusions of CAR T-cell therapy that targeted CD22 followed by CD20 according to their disease status and CAR T-cell persistence after each infusion. The median time from the last infusion to the cutoff date was 17 months (range, 15-23 months). The estimated 18-month CR rate was 78% (95% confidence interval [CI], 54%-91%). The estimated 18-month progression-free survival rate was 78% (95% CI, 55%-90%), with 78% (95% CI, 37%-94%) in patients with bulky disease and 60% (95% CI, 25%-83%) in patients with central nervous system (CNS) involvement. During the first CD19 CAR T-cell infusion, grade ≥3 cytokine release syndrome (CRS) occurred in 34.8% and neurotoxicity occurred in 21.7% of all patients. During subsequent infusions, there were only a few incidences of grade >2 CRS and neurotoxicity. All adverse events were reversible. The severity of neurotoxicity was not significantly different between patients with CNS involvement and those who did not have CNS involvement. Sequential CAR T-cell therapy may result in a durable response and is safe in pediatric R/R Burkitt lymphoma. Patients with CNS involvement may benefit from sequential CAR T-cell therapy. This trial was registered at www.chictr.org.cn/index.aspx as #ChiCTR1800014457.

Diagnosis and treatment of pediatric anaplastic lymphoma kinase-positive large B-cell lymphoma: A case report.

BACKGROUND: Anaplastic lymphoma kinase-positive (ALK+) large B-cell lymphoma (LBCL) is a rare type of lymphoma with high invasiveness and rapid progression. It occurs in all age groups, but is extremely rare in children. The lesions mainly involve the lymph nodes and may present with extra-nodal involvement. Response to conventional chemotherapies and local radiotherapy is poor, with a 5-year overall survival of less than 40%. Recently, the use of ALK inhibitors for the treatment of this disease has been reported. CASE SUMMARY: We present a case of a 12-year-old boy diagnosed with ALK+LBCL. The patient had a 2-mo medical history of a calvarial mass, extensive systemic involvement, and positive bone marrow clathrin heavy chain (CLTC)-ALK fusion gene. Complete remission 1 (CR1) was achieved using the modified LMB89 Group C regimen followed by autologous stem cell transplantation. The patient relapsed 3 mo later. He then achieved CR2 with three short courses of chemotherapy (COP, reduced-dose ICE, low-dose Ara-c+VP16) and continuous alectinib targeted therapy. Afterward, allogeneic hematopoietic stem cell transplantation (allo-HSCT) was performed. At 16 mo after the allo-HSCT, the patient was still in CR2. CONCLUSION: The modified LMB89 Group C regimen and ALK inhibitors are effective. Allo-HSCT should be performed after remission.

Case Report: EBV-Positive Extra-Nodal Marginal Zone Lymphoma Associated With XMEN Disease Caused by a Novel Hemizygous Mutation in MAGT1.

BACKGROUND: X-linked immunodeficiency with magnesium defect and Epstein-Barr virus infection and neoplasia (XMEN) disease is an X-linked genetic disorder of immune system caused by loss-of-function mutation in gene encoding Magnesium transporter 1 (MAGT1). Individuals with XMEN disease are prone to developing Epstein Barr Virus (EBV)-associated lymphomas. Herein, we report the first known case of an EBV+ EMZL associated with XMEN disease. CASE PRESENTATION: The patient was an 8-year-old Chinese boy who suffered from recurrent infections from birth. Six months before, the patient presented with a painless mass on his upper lip and excisional biopsy revealed an EBV-positive extra-nodal marginal zone lymphoma (EBV+ EMZL). Furthermore, molecular investigations with next-generation sequencing identified a novel germline mutation in MAGT1 (c.828_829insAT) in the patient. The c.828_829insAT variant was predicted to cause premature truncation of MAGT1 (p.A277M.fs*11) and consequently was defined as likely pathogenic. The mutation was inherited from his asymptomatic heterozygous carrier mother. Hence the patient was diagnosed with an XMEN disease both clinically and genetically. CONCLUSION: Our results expand the genetic spectrum of XMEN disease and also the clinical spectrum of EBV+ EMZL. We highlight the importance of the genetic etiology underlying EBV+ lymphoma in the pediatric population.

Meta-analysis investigating the relationship between clinical features, outcomes, and severity of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pneumonia.

OBJECTIVE: We aimed to investigate the relationship between clinical characteristics, outcomes and the severity of severe acute respiratory syndrome coronavirus 2 pneumonia. METHODS: We performed a systematic review and meta-analysis using PubMed, Embase, and Cochrane Library databases to assess the clinical characteristics and outcomes of confirmed COVID-19 cases and compared severe (ICU) and nonsevere (non-ICU) groups. RESULTS: We included 12 cohort studies including 2,445 patients with COVID-19. Compared with nonsevere (non-ICU) patients, severe (ICU) disease was associated with a smoking history (P = .003) and comorbidities including chronic obstructive pulmonary disease (OR = 5.08, P < .001), diabetes (OR = 3.17, P < .001), hypertension (OR = 2.40, P < .001), coronary heart disease (OR = 2.66, P < .001), cerebrovascular diseases (OR = 2.68, P = .008), and malignancy (OR=2.21, P = .040). We found significant differences between the 2 groups for fever, dyspnea, decreased lymphocyte and platelet counts, and increased leukocyte count, C-creative protein, procalcitonin, lactose dehydrogenase, aspartate aminotransferase, alanine aminotransferase, creatinine kinase, and creatinine levels (P < .05). Significant differences were also observed for multiple treatments (P < .05). Patients in the severe (ICU) group were more likely to have complications and had a much higher mortality rate and lower discharge rate than those with nonsevere (non-ICU) disease (P < .05). CONCLUSIONS: Investigation of clinical characteristics and outcomes of severe cases of COVID-19 will contribute to early prediction, accurate diagnosis, and treatment to improve the prognosis of patients with severe illness.

Angioimmunoblastic T-cell lymphoma contains multiple clonal T-cell populations derived from a common TET2 mutant progenitor cell.

Angioimmunoblastic T-cell lymphoma (AITL) is a neoplastic proliferation of T follicular helper cells with clinical and histological presentations suggesting a role of antigenic drive in its development. Genetically, it is characterized by a stepwise acquisition of somatic mutations, with early mutations involving epigenetic regulators (TET2, DNMT3A) and occurring in haematopoietic stem cells, with subsequent changes involving signaling molecules (RHOA, VAV1, PLCG1, CD28) critical for T-cell biology. To search for evidence of potential oncogenic cooperation between genetic changes and intrinsic T cell receptor (TCR) signaling, we investigated somatic mutations and T-cell receptor ß (TRB) rearrangement in 119 AITL, 11 peripheral T-cell lymphomas with T follicular helper phenotype (PTCL-TFH), and 25 PTCL-NOS using Fluidigm polymerase chain reaction (PCR) and Illumina MiSeq sequencing. We confirmed frequent TET2, DNMT3A, and RHOA mutations in AITL (72%, 34%, 61%) and PTCL-TFH (73%, 36%, 45%) and showed multiple TET2 mutations (2 or 3) in 57% of the involved AITL and PTCL-TFH. Clonal TRB rearrangement was seen in 76 cases with multiple functional rearrangements (2-4) in 18 cases (24%). In selected cases, we confirmed bi-clonal T-cell populations and further demonstrated that these independent T-cell populations harboured identical TET2 mutations by using BaseScope in situ hybridization, suggesting their derivation from a common TET2 mutant progenitor cell population. Furthermore, both T-cell populations expressed CD4. Finally, in comparison with tonsillar TFH cells, both AITL and PTCL-TFH showed a significant overrepresentation of several TRB variable family members, particularly TRBV19*01. Our findings suggest the presence of parallel neoplastic evolutions from a common TET2 mutant haematopoietic progenitor pool in AITL and PTCL-TFH, albeit to be confirmed in a large series of cases. The biased TRBV usage in these lymphomas suggests that antigenic stimulation may play an important role in predilection of T cells to clonal expansion and malignant transformation. © 2019 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.

Prognostic significance of locally invaded sites and tissue types in patients with nasal extranodal natural-killer/T-cell lymphoma: a single-center retrospective analysis.

BACKGROUND: Extranodal natural killer/T-cell lymphoma (ENKTL), nasal type, is an aggressive entity within the World Health Organization classification of lymphoid tumors. The International Prognostic Index is reported to be prognostically meaningful for ENKTL, but lacks discriminatory power for stage I/II ENKTL with extensive local invasion. This study aimed to evaluate the prognostic effects of local invasion by site and tissue type in patients with ENKTL. METHODS: We retrospectively analyzed data of 86 patients who were diagnosed with ENKTL by the Department of Pathology of Beijing Tongren Hospital from June 2002 to April 2016, and ascertained tumor infiltration of adjacent structures (AS), bone, and soft tissue for each patient, using physical findings and imaging scans. We used univariate and multivariate analysis to assess the association of each involved tissue or site with patients' overall survival (OS). RESULTS: Of the 86 patients, 71 (82.6%) experienced invasion of AS, 22 (25.6%) of soft tissue, and 26 (30.2%) had bone involvement. Overall, patients with AS involvement did not show significantly shorter survival than those without AS involvement (Log rank χ = 1.177, P = 0.278); however, patients who had involved eyeballs or brains showed significantly lower 2-year OS rates than those without eyeball involvement (Log rank χ = 4.105, P = 0.043) or brain involvement (Log rank χ = 7.126, P = 0.008). Patients with involved local soft tissue or bones, respectively, showed lower 2-year OS rates than those without involved local soft tissue (Log rank χ = 10.390, P = 0.001) or bones (Log rank χ = 8.993, P = 0.003). Multivariate analysis showed that involvement of the cheek or facial muscles (hazard ratio, HR = 5.471, 95% confidence interval [CI]: 1.466-20.416, P = 0.011) and the maxilla bone (HR = 6.120, 95% CI: 1.517-24.694, P = 0.011) were significantly independent predictors of lower 2-year OS rates. CONCLUSIONS: Imaging can accurately detect ENKTL invasion of AS, soft tissue, and bone. Involvement of local soft tissue or bone was significantly associated with lower 2-year OS rates. Involvements of the cheek or facial muscle, as well as maxilla bone, are independent predictors of lower 2-year OS rates in ENKTL patients.

Angioimmunoblastic T cell lymphoma: novel molecular insights by mutation profiling.

Angioimmunoblastic T cell lymphoma (AITL) originates from follicular helper T-cells and is characterised by a polymorphic infiltrate with the neoplastic T-cells forming small clusters around the follicle and high endothelial venules. Despite the recent advances in its phenotypic characterisation, the genetics and molecular mechanisms underlying AITL are not fully understood. In the present study, we performed whole exome sequencing in 9 cases of AITL from Taiwan (n = 6) and U.K. (n = 3). We confirmed frequent mutations in TET2 (9/9), DNMT3A (3/9), IDH2 (3/9), RHOA (3/9) and PLCG1 (2/9) as recently reported by others. More importantly, we identified mutations in TNFRSF21 (1/9), CCND3 (1/9) and SAMSN1 (1/9), which are not yet seen or strongly implicated in the pathogenesis of AITL. Among the pathogenic mutations identified in AITL, mutations in DNA methylation regulators TET2 and DNMT3A occur early in hematopoietic stem cells as shown by previous studies, and these genetic events enhance the self-renewal of hematopoietic stem cells, but are unlikely to have any major impact on T-cell differentiation. Mutations in RHOA, PLCG1 and TNFRSF21 (DR6), which encode proteins critical for T-cell biology, most likely promote T-cell differentiation and malignant transformation, consequently generating the malignant phenotype. Our findings extend the molecular insights into the multistage development of AITL.

ALK-positive Large B-cell Lymphoma: A Clinicopathologic Study of 26 Cases With Review of Additional 108 Cases in the Literature.

Anaplastic lymphoma kinase-positive large B-cell lymphoma (ALK LBCL) is a rare, aggressive subtype of diffuse large B-cell lymphoma with characteristic ALK rearrangements. Diagnosis of ALK LBCL can be challenging because of its rarity, unique morphologic characteristics, and unusual immunophenotypic features, which significantly overlap with other hematologic and nonhematologic neoplasms. The purpose of this study is to further explore the clinicopathologic features of ALK LBCL to ensure the awareness and accurate diagnosis of this entity. We retrospectively reviewed the data from 26 cases in our institutions and additional 108 cases from the literature. ALK LBCL typically occurred in the lymph nodes of young and middle-aged, immunocompetent patients. The medium age was 35 years with a male to female ratio of 3.5:1. Vast majority of cases showed immunoblastic and/or plasmablastic morphology. All cases expressed ALK protein with a cytoplasmic granular pattern in most of them. Common B-cell markers (CD20, CD79a, and PAX5) were typically negative, but the tumor cells mostly expressed 2 B-cell transcriptional factors, BOB1 and OCT2. The 5-year overall survival (OS) was 34%, and the median survival was 1.83 years. In patients with stage III/IV disease, the 5-year OS was only 8%. Moreover, patients below 35 years of age had a significantly better OS than those aged 35 years or above.

Oct2 and Bob1 are sensitive and specific markers in lineage determination of B cell lymphomas with no expression of conventional B cell markers.

AIMS: Rare cases of B cell lymphomas do not express conventional B cell markers (CD20, CD79a and PAX5), and these types of lymphomas include anaplastic lymphoma kinase (ALK)-positive large B cell lymphoma, plasmablastic lymphoma, primary effusion lymphoma and the solid variant of primary effusion lymphoma, extracavitary human herpesvirus 8 (HHV8)-positive large B cell lymphoma. Establishing accurate diagnoses of these B cell lymphomas can be challenging, and often requires a large panel of immunohistochemical stains, molecular assays and cytogenetic studies. B cell-specific transcription factors, Oct2 and Bob1, have been shown to be expressed consistently in most, if not all, B cell lymphomas, and therefore we investigated the utility of Oct2 and Bob1 immunohistochemistry in lineage determination of the aforementioned B cell lymphomas. METHODS AND RESULTS: We selected 34 cases of previously diagnosed B cell lymphomas with no or weak expression of CD20, CD79a and PAX5. Oct2 and Bob1 were positive in 74% (25 of 34) and 85% (29 of 34) of the cases, respectively. When we combined the results of these two immunostains, 94% (32 of 34) cases expressed at least one of these two markers. We also included 51 control cases of non-B cell neoplasms, and none of them expressed either Oct2 or Bob1. CONCLUSIONS: Oct2 and Bob1 are very reliable in determining B cell lineage in the absence of expression of other pan-B cell markers, and it should provide great diagnostic benefit to include them both in a panel of immunohistochemistry to assess undifferentiated malignant neoplasms.

[Expression of microRNA-191 in T lymphoblastic leukemia/lymphoma and its underlying mechanism].

OBJECTIVE: To evaluate the correlation between MicroRNA-191 (miR-191) and T lymphoblastic leukemia/lymphoma (T-ALL/LBL) to probe its underlying molecular mechanism. METHODS: The expression of miR-191 was examined by real-time PCR (RT-PCR) in 20 T-ALL/LBL tissue samples and 20 lymphoid reactive hyperplasia (LRH) tissue samples. The correlation between miR-191 and the clinicopathological feature of T-ALL/LBL was analyzed. Antisense miR-191 lentiviral vectors was constructed and transfected into T-ALL/LBL Jukat cells. After transfection, the expression of miR-191 was examined by RT-PCR. The cell activity was evaluated by CCK-8 asssy. The cell cycle and apoptosis were determined by flow cytometry. RESULTS: Compared with LRH samples, the results of RT-PCR showed significant upregulation of miR-191 in 20 T-ALL/LBL tissue samples (1.875±0.079 vs 1.000, P<0.05). The expression level of miR-191 was negatively associated with prognosis. Compared with LV-NC-GFP and control groups, the expression of miR-191 significantly decreased after transfection of antisense miR-191 lentiviral vectors (0.578±0.012 vs 1.011±0.053 and 1.000, P<0.05), the percentages of apoptotic cells and the cell in G0/G1 phase significantly increased (P<0.05). CONCLUSIONS: miR-191 might play a significant role in the development of T-ALL/LBL, implicating a new target for therapy.

[Expression and prognostic value of COX- 2, p16(INK4A) and p53 in patients with classical Hodgkin lymphoma].

OBJECTIVE: To investigate the expression level of COX-2, p16(INK4A) and p53 in patients with classic Hodgkin's lymphoma (cHL), and to evaluate their correlation with prognosis. METHODS: The clinical data and samples of 52 cHL cases were collected. Immunohistochemical staining was performed to analyze the proteins level mentioned above and in situ hybridization of EBV encoded RNA (EBER) to clarify the tumor EBV infection state. Correlation between the protein expression and prognosis of patients was analyzed. RESULTS: Of 52 cases, the male and female ratio was 1.6∶1, the age was from 22 to 68 years old. All lesions located primarily in lymph nodes. All samples from 52 cases were stained with COX-2, p16(INK4A) and p53, and the positive expression of COX-2 was found in 28 cases (53.8%）, that of p16(INK4A) in 25 cases (48.1%)and p53 in 42 cases (80.8%）. All patients were divided into two groups according to differences in age (<40 years/ ≥ 40 years), gender (male/female), EBV infection (yes/no), B symptoms (yes/no), and the Ann Arbor staging (Ⅰ-Ⅱ/Ⅲ-Ⅳ), the correlation with COX-2, p16(INK4A) and p53 expression were analyzed, and only p53 expression was correlated with Ann Arbor staging (P=0.027). The statistical analysis of correlations between COX- 2, p16(INK4A) and p53 showed that the expression of COX-2 was strongly correlated with p53 (P=0.008), and p16 (INK4A) was not related to either COX-2 or p53 (P=0.246 and 0.958). Kaplan- Meier univariate OS analysis using SPSS17.0 software showed that only COX-2 expression was an adverse prognostic factor for patients'event free survival (EFS) (P=0.003). Meanwhile COX-2 expression was a unique independent prognostic factor analyzed by COX proportional hazards regression model (HR=0.091, 95% CI 0.017-0.505, P=0.006). CONCLUSION: The expression rate of COX-2, p16 (INK4A) and p53 in the cHL were relatively high; and they were not statistically correlated with tumor EBV infection status; the COX-2 positive group had poor prognosis, but only event free survival time becomes statistically significant shorter. COX proportional hazard regression model was used to analyze the COX-2 expression as a independent adverse prognostic factors for EFS.

[Testicular lymphoma: a clinicopathological study of 65 cases].

OBJECTIVE: To summarize the clinicopathological features of testicular lymphomas (TL). METHODS: The medical records of 65 patients diagnosed with TL between 2008.1.1 and 2014.11.30 were retrospectively reviewed. RESULTS: TL was classified as primary (PTL) when there's no prior diagnosis of an extara-testicular lymphoma/leukemia and no concurrent widespread disease, except for the concomitant involvement of ipsilateral inguinal lymph nodes; otherwise it was classified as secondary (STL). Of our patients group, 46 (70.8%) cases were classified primary TL as and the other 19 (29.2%） cases were secondary TL. All patients presented with painless testicular swelling. The median age of STL was significantly younger than that of PTL [65 (12-88) ys vs 13 (1-75) ys, P<0.001]. Additionally, a striking difference in the distribution of histological subtypes was observed between the PTL and STL patients group. CONCLUSION: Primary TLs were more common than secondary. Striking differences in the distribution of patients'age and histology were found between STL and PTL.

Plasmablastic lymphoma of the stomach with C-MYC rearrangement in an immunocompetent young adult: a case report.

Plasmablastic lymphoma (PBL) is a rare B-cell neoplasm mostly described in human immunodeficiency virus-infected patients. Herein, we described a case of PBL presenting as gastric mass in a 21-year-old young adult without known immunodeficiency. The histological examination of the specimen showed a diffuse proliferation of round- to oval-shaped large cells with scant cytoplasm, and prominent nucleoli. The neoplasm stained positively for CD45, CD38, MUM1, and Vs38C, but typical B-cell and T-cell markers (PAX5, CD20, CD79a, and CD3) were absent. The proliferative index (Ki-67) was about 95%. And the neoplastic cells diffusely expressed the c-myc protein. Epstein-Barr virus-encoded RNA in situ hybridization was negative. Molecular genetic study via interphase fluorescence in situ hybridization disclosed the rearrangement involving c-myc gene. Awareness of this distinctive lymphoma can prevent misdiagnosis by the clinicians and/or the pathologists.

Diffuse large B-cell lymphoma: sub-classification by massive parallel quantitative RT-PCR.

Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous entity with remarkably variable clinical outcome. Gene expression profiling (GEP) classifies DLBCL into activated B-cell like (ABC), germinal center B-cell like (GCB), and Type-III subtypes, with ABC-DLBCL characterized by a poor prognosis and constitutive NF-κB activation. A major challenge for the application of this cell of origin (COO) classification in routine clinical practice is to establish a robust clinical assay amenable to routine formalin-fixed paraffin-embedded (FFPE) diagnostic biopsies. In this study, we investigated the possibility of COO-classification using FFPE tissue RNA samples by massive parallel quantitative reverse transcription PCR (qRT-PCR). We established a protocol for parallel qRT-PCR using FFPE RNA samples with the Fluidigm BioMark HD system, and quantified the expression of the COO classifier genes and the NF-κB targeted-genes that characterize ABC-DLBCL in 143 cases of DLBCL. We also trained and validated a series of basic machine-learning classifiers and their derived meta classifiers, and identified SimpleLogistic as the top classifier that gave excellent performance across various GEP data sets derived from fresh-frozen or FFPE tissues by different microarray platforms. Finally, we applied SimpleLogistic to our data set generated by qRT-PCR, and the ABC and GCB-DLBCL assigned showed the respective characteristics in their clinical outcome and NF-κB target gene expression. The methodology established in this study provides a robust approach for DLBCL sub-classification using routine FFPE diagnostic biopsies in a routine clinical setting.

Distribution of enterovirus 71 RNA in inflammatory cells infiltrating different tissues in fatal cases of hand, foot, and mouth disease.

In previous studies of hand, foot, and mouth disease patients fatally infected with enterovirus 71 (EV71), the distribution of viral protein, but not the genome, was determined. To understand the pathogenesis of EV71, however, it is important to investigate the spread of the viral genome. There have been no pathological studies of in situ EV71 viral RNA in inflammatory cells infiltrating various tissues of fatal cases. We therefore first investigated the distribution and classification of inflammatory cells in various tissues and then performed in situ EV71 RNA hybridization in these tissues to better understand the pathogenesis of EV71 infection. EV71 RNA was found mainly in inflammatory cells infiltrating the central nervous system (CNS), intestines, lungs, and tonsils. Most EV71 RNA-positive inflammatory cells in the CNS were macrophages/microglia and neutrophils infiltrating the perivascular cuffing, microglial nodule, neuronophagia, and meninges. CD68+ macrophages and CD15+ neutrophils were diffusely distributed in tissues with severe pathological changes. This study demonstrates the presence of EV71 RNA in inflammatory cells infiltrating tissues in fatally infected patients. Our findings suggest that fatal EV71 infection with extensive infiltration of macrophages/microglia and neutrophils into the CNS results in severe neurological lesions.