Clinicopathological comparison between PTCL-TBX21 and PTCL-GATA3 in Japanese patients.

AIM: Peripheral T-cell lymphoma not otherwise specified (PTCL-NOS) is a heterogeneous disease that can be classified into the PTCL-TBX21 and PTCL-GATA3 subtypes. METHODS: In this study, we compared the clinicopathological features of PTCL-NOS in a Japanese cohort, classified using an IHC algorithm. RESULTS: One hundred patients with PTCL-NOS were categorized as having PTCL-TBX21 (n = 55), PTCL-GATA3 (n = 24), or PTCL-unclassified (n = 21). When comparing PTCL-TBX21 and PTCL-GATA3, PTCL-TBX21 showed significantly lower CD4 positivity (p = 0.047), lower counts of high endothelial venules (p = 0.032), and a tendency for a better response to initial treatment (p = 0.088). Gene expression analysis using the nCounter system showed higher expression of tumor immunity-related genes, such as PD-L1, LAG3, and IDO1, in PTCL-TBX21 than in PTCL-GATA3. PTCL-GATA3 had significantly worse overall survival (OS) than those with PTCL-TBX21 (p = 0.047), although a similar tendency was observed for progression-free survival (PFS) (p = 0.064). PTCL-GATA3 was a prognostic factor for OS in univariate analysis (HR 2.02; 95% CI, 1.09-3.77; p = 0.027), although multivariate analysis did not show significance (HR 2.07; 95% CI, 0.93-4.61; p = 0.074). In the PFS analysis, PTCL-GATA3 was an independent prognostic factor by univariate analysis (HR 1.96; 95% CI, 1.08-3.56; p = 0.027) and multivariate analysis (HR 2.34; 95% CI, 1.07-5.11; p = 0.032). CONCLUSION: The classification of PTCL-NOS into PTCL-TBX21 and PTCL-GATA3 is useful for predicting the prognosis of Japanese patients and stratifying the administration of tumor immune checkpoint inhibitors in clinical practice.

Co-expression of regulatory B-cell markers, transforming growth factor ß and interleukin-10 as a prognostic factor in diffuse large B-cell lymphoma.

Regulatory B cells (Bregs) suppress antitumor immunity by producing anti-inflammatory cytokines such as transforming growth factor ß (TGF-ß) and interleukin-10 (IL-10) and promoting tumor growth. It is unknown whether diffuse large B-cell lymphoma (DLBCL), a common subtype of B-cell malignancy, exhibits characteristics similar to those of Bregs. This study aimed to clarify the features of DLBCLs carrying Breg markers. In 123 DLBCL cases, we evaluated TGF-ß and IL-10 expression in tumor biopsy samples using immunohistochemical staining and retrospectively analyzed their clinicopathological characteristics. Fifteen cases (12.2 %) classified as Breg-type DLBCL were positive for both TGF-ß and IL-10. Breg-type DLBCL is mainly classified as having activated B cell-like cells of origin. Breg-type DLBCL cases showed significantly worse progression-free survival and overall survival (OS) than other DLBCL cases (P = 0.0016 and P = 0.042, respectively). In multivariate analysis, Breg-type DLBCL significantly affected OS (hazard ratio, 3.13; 95 % confidence interval 1.15-8.55; P = 0.025). Gene expression analysis showed that the expression of follicular dendritic cell-associated genes (FCER2, PIK3CD, FOXO1) was downregulated in Breg-type DLBCLs compared to other DLBCLs. These results suggest that the double expression of Breg markers, TGF-ß and IL-10, in tumor cells indicates a poor prognosis in DLBCL patients. Further studies evaluating genomic abnormalities could confirm the characteristics of Breg-type DLBCL.

Primary renal peripheral T-cell lymphoma, not otherwise specified, treated with partial nephrectomy.

Introduction: Renal involvement by non-Hodgkin's lymphoma is very rare, and the kidney as the primary site of this lymphoma is much more uncommon. We report a case of primary renal peripheral T-cell lymphoma, not otherwise specified, treated with partial nephrectomy. Case presentation: A 63-year-old man was hospitalized with coronavirus infectious disease, emerged in 2019 in the emergency department. Computed tomography examination showed a 2-cm renal mass in the right kidney. Abdominal enhanced computed tomography examination revealed that the noted mass showed good enhancement in the corticomedullary phase and washout in the nephrogenic phase. No metastatic lesions were found. He was diagnosed as having cT1aN0M0 renal cell carcinoma, and robotic-assisted partial nephrectomy was carried out. The pathological diagnosis was peripheral T-cell lymphoma, not otherwise specified. He has been followed for 20 months after robotic-assisted partial nephrectomy without additional treatment and recurrence. Conclusion: We experienced a primary renal peripheral T-cell lymphoma, not otherwise specified that was followed up without treatment after surgery.

The Detection of Neoplastic Cells Using Objective Cytomorphologic Parameters in Malignant Lymphoma.

Pathologic evaluation is the most crucial method for diagnosing malignant lymphomas. However, there are no established diagnostic criteria for evaluating pathologic morphology. We manually circled cell nuclei in the lesions of 10 patients with diffuse large B-cell lymphoma (DLBCL), follicular lymphoma, and reactive lymphadenitis. Seventeen parameters related to nuclear shape, color, and other characteristics were measured. We attempted to compare the statistical differences between these subtypes and extract distinctive disease-specific populations on the basis of these parameters. Statistically significant differences were observed between the different types of lymphoma for many of the 17 parameters. Through t-distributed stochastic neighbor embedding analysis, we extracted a cluster of cells that showed distinctive features of DLBCL and were not found in follicular lymphoma or reactive lymphadenitis. We created a decision tree to identify the characteristics of the cells within that cluster. Based on a 5-fold cross-validation study, the average sensitivity, specificity, and accuracy obtained were 84.1%, 98.4%, and 97.3%, respectively. A similar result was achieved using a validation experiment. Important parameters that indicate the features of DLBCL include Area, ConcaveCount, MaxGray, and ModeGray. By quantifying pathologic morphology, it was possible to objectively represent the cell morphology specific to each lymphoma subtype using quantitative indicators. The quantified morphologic information has the potential to serve as a reproducible and flexible diagnostic tool.

Clinicopathological analysis of CD47 and signal regulatory protein alpha expression in myeloid sarcoma patients: CD47 expression is a favourable prognostic factor.

Myeloid sarcoma is a rare extramedullary haematopoietic malignancy. Interaction between CD47 and signal regulatory protein α (SIRPα) inhibits phagocytosis. CD47-positive tumours confer poor prognoses in various malignant tumours, including acute myeloid leukaemia. This study aimed to investigate the clinicopathological effects of CD47 and SIRPα expression in myeloid sarcoma. Immunohistochemistry (IHC) of CD47 and SIRPα was performed in 84 biopsy samples obtained from patients with myeloid sarcoma, some of which were CD47-positive. Patients were categorised into the following two groups based on IHC of SIRPα: those with SIRPα-positive neoplastic cells (nSIRPα) and, SIRPα expression on non-neoplastic stromal cells in tumour microenvironment (miSIRPα). In addition, patients with CD47 positivity had higher lymphocytic infiltration into the tumour microenvironment. Overall, these patients had significantly higher overall survival, however, no significant difference was observed in progression-free survival. No significant prognostic differences were observed between the nSIRPα and miSIRPα groups. This is the first study to demonstrate an association between CD47 expression and improved prognosis in myeloid sarcoma. Nonetheless, it will be necessary to conduct additional research on gene expression and genomic abnormalities to elucidate the corresponding pathogenesis of myeloid sarcoma.

Digital spatial profiling of CD4+ T cells in classic Hodgkin lymphoma.

Classic Hodgkin lymphoma (CHL) harbors a small number of Hodgkin-Reed-Sternberg (HRS) cells scattered among numerous lymphocytes. HRS cells are surrounded by distinct CD4+ T cells in a rosette-like manner. These CD4+ T cell rosettes play an important role in the tumor microenvironment (TME) of CHL. To elucidate the interaction between HRS cells and CD4+ T cell rosettes, we completed digital spatial profiling to compare the gene expression profiles of CD4+ T cell rosettes and other CD4+ T cells separated from the HRS cells. Immune checkpoint molecules including OX40, programed cell death-1 (PD-1), and cytotoxic T lymphocyte associated protein 4 (CTLA-4) expression was higher in CD4+ T cell rosettes compared to other CD4+ T cells. Immunohistochemistry confirmed variable PD-1, CTLA-4, and OX40 expression in the CD4+ T cell rosettes. This study introduced a new pathological approach to study the CHL TME, and provided deeper insight into CD4+ T cells in CHL.

HTLV-1 bZIP Factor-Induced Reprogramming of Lactate Metabolism and Epigenetic Status Promote Leukemic Cell Expansion.

Acceleration of glycolysis is a common trait of cancer. A key metabolite, lactate, is typically secreted from cancer cells because its accumulation is toxic. Here, we report that a viral oncogene, HTLV-1 bZIP factor (HBZ), bimodally upregulates TAp73 to promote lactate excretion from adult T-cell leukemia-lymphoma (ATL) cells. HBZ protein binds to EZH2 and reduces its occupancy of the TAp73 promoter. Meanwhile, HBZ RNA activates TAp73 transcription via the BATF3-IRF4 machinery. TAp73 upregulates the lactate transporters MCT1 and MCT4. Inactivation of TAp73 leads to intracellular accumulation of lactate, inducing cell death in ATL cells. Furthermore, TAp73 knockout diminishes the development of inflammation in HBZ-transgenic mice. An MCT1/4 inhibitor, syrosingopine, decreases the growth of ATL cells in vitro and in vivo. MCT1/4 expression is positively correlated with TAp73 in many cancers, and MCT1/4 upregulation is associated with dismal prognosis. Activation of the TAp73-MCT1/4 pathway could be a common mechanism contributing to cancer metabolism. SIGNIFICANCE: An antisense gene encoded in HTLV-1, HBZ, reprograms lactate metabolism and epigenetic modification by inducing TAp73 in virus-positive leukemic cells. A positive correlation between TAp73 and its target genes is also observed in many other cancer cells, suggesting that this is a common mechanism for cellular oncogenesis. This article is featured in Selected Articles from This Issue, p. 337.

Case-based similar image retrieval for weakly annotated large histopathological images of malignant lymphoma using deep metric learning.

In the present study, we propose a novel case-based similar image retrieval (SIR) method for hematoxylin and eosin (H&E) stained histopathological images of malignant lymphoma. When a whole slide image (WSI) is used as an input query, it is desirable to be able to retrieve similar cases by focusing on image patches in pathologically important regions such as tumor cells. To address this problem, we employ attention-based multiple instance learning, which enables us to focus on tumor-specific regions when the similarity between cases is computed. Moreover, we employ contrastive distance metric learning to incorporate immunohistochemical (IHC) staining patterns as useful supervised information for defining appropriate similarity between heterogeneous malignant lymphoma cases. In the experiment with 249 malignant lymphoma patients, we confirmed that the proposed method exhibited higher evaluation measures than the baseline case-based SIR methods. Furthermore, the subjective evaluation by pathologists revealed that our similarity measure using IHC staining patterns is appropriate for representing the similarity of H&E stained tissue images for malignant lymphoma.

Clinicopathological analysis of immunohistochemical expression of immune checkpoint molecules in follicular lymphoma.

Follicular lymphoma (FL) is characterized by an indolent clinical course and a high relapse rate, and often exhibits a diffuse pattern beyond the follicular area. Our group previously reported that immune checkpoint (ICP) pathways, such as programmed cell death (PD-1) and programmed death ligand 1 (PD-L1), are poor prognostic factors for diffuse large B-cell lymphoma and adult T-cell leukemia/lymphoma. In this study, the association between the expression of multiple ICP molecules according to immunohistochemistry and clinicopathological features in FL was determined via immunostaining of 173 biopsy samples. Membrane and/or cytoplasm expression of CD86 (nCD86) and PD-L1 (nPD-L1) was found in tumor cells, whereas PD-1 (miPD-1), Galectin-9 (miGalectin-9), OX40 (miOX40), CTLA-4 (miCTLA-4), Tim-3 (miTim-3), OX40L (miOX40L), and LAG-3 (miLAG-3) were expressed in non-neoplastic stromal cells. MiPD-1 expression was significantly higher in the follicular area than in the diffuse area (p = 0.0450). Expression of miOX40 and miCTLA-4 was significantly higher in the diffuse area than in the follicular area (respectively, p = 0.0053 and p = 0.0092). MiTim-3 tended to be higher in the diffuse area than in the follicular area (p = 0.0616). MiTim-3 was significantly higher in relapse cases than in new-onset cases (p = 0.0440); miLAG-3 tended to be higher in relapse cases than in new-onset cases (p = 0.0622, not significant). The miOX40L-high FL group had a significantly worse overall survival than the miOX40L-low group (p = 0.0320). The expression of multiple ICP molecules on several cells reflects activated anti-tumor immunity and the unique FL microenvironment. Further studies on gene expression or genomic abnormalities will reveal the clinical and biological significance of ICP molecules in FL.

CD37 expression in follicular lymphoma.

CD37 is a tetraspanin protein expressed in various B-cell lymphomas that mediates tumor survival signaling. Follicular lymphoma (FL) is a representative B-cell neoplasm composed of germinal center B cells. In recent years, CD37 has been focused on as a therapeutic target for B-cell lymphoma. The purpose of this study was to characterize CD37 expression in FL patients to identify risk factors associated with various prognostic factors. We retrospectively reviewed 167 cases of FL and evaluated the immunohistochemical expression of CD37 and its statistical association with clinicopathological features. Immunohistochemically, CD37 was observed in the cytoplasm and/or membrane of neoplastic cells, mainly in neoplastic follicles to various extents. One hundred cases (100/167, 60.0%) were categorized as CD37-positive, and 67 cases were CD37-negative. In cases with high Follicular Lymphoma International Prognostic Index (FLIPI), CD37-negative cases had a poor overall survival compared with CD37-positive cases (P = 0.047), although no significant differences were observed in other clinicopathologic factors, including histological grade, BCL2-IGH translocation, and immunohistochemical phenotype. Therefore, CD37 protein may play a role in tumor progression and may serve as a therapeutic target. However, further studies are needed to explore its significance.

Clinicopathological analysis of myeloid sarcoma with megakaryocytic differentiation.

Myeloid sarcoma (MS) is defined as a tumour mass consisting of myeloid blasts that occurs at an anatomical site other than bone marrow. MS with megakaryocytic differentiation (MSmgk) is extremely rare and its clinicopathological features have not been well described. We reviewed 11 cases in 11 patients of extramedullary mass-forming malignant tumours composed of immature non-lymphoid haematopoietic cells expressing CD41 with or without concurrent bone marrow lesions. The patients consisted of seven men and four women (1.75:1 male-to-female ratio). The mean and median ages at diagnosis were 50 and 62 years, respectively, ranging from 2 to 78 years. Extramedullary mass lesions were solitary in three cases (27%) and multiple in eight cases (73%). Tumour locations were lymph nodes (6 cases), subcutaneous tissue (3 cases), intramuscular (1 case), and bone (1 case). Seven of the 11 patients (64%) had a history of myelodysplastic syndrome (MDS) or myeloproliferative neoplasm (MPN). Three patients (27%) developed MS during remissions of acute myelogenous leukaemia, and one patient had a recurrence of MS at other sites. Follow-up data were available for four cases. Tumour cells were positive for CD41, CD33, CD34, MPO, and CD68 in 11 (100%), three (27%), seven (64%), four (36%), and seven (64%) cases, respectively. Cytogenetic analysis was successfully performed in two cases. Complex but inconsistent abnormalities were evident. When compared with cases of MS without megakaryocytic differentiation, the survival of MSmgk was significantly shorter (p=0.0033). Compared to MS without megakaryocytic differentiation, MSmgk is more likely to follow MDS/MPN, to involve multiple sites, and to be associated with poorer outcomes. More detailed studies, including genomic or gene expression analyses, could confirm the characteristics of MSmgk.

Primary Pulmonary Mucosa-associated Lymphoid Tissue Lymphoma with the High Expression of IgG4.

This is the first report describing primary pulmonary mucosa-associated lymphoid tissue (MALT) lymphoma with the high expression of IgG4. The histological findings were compatible with the diagnostic criteria for MALT lymphoma and IgG4-related respiratory disease (IgG4-RRD). An unfixed sample for Southern blotting was not obtained since computed tomography findings showed multiple lung cysts, which is rare in patients with MALT lymphoma. However, polymerase chain reaction using paraffin sections showed the clonality of the immunoglobulin heavy chain variable region gene rearrangement, confirming a diagnosis of MALT lymphoma. This is an instructive case in which primary pulmonary MALT lymphoma was histologically compatible with IgG4-RRD.

Expression of telomerase reverse transcriptase in peripheral T-cell lymphoma.

Telomere length is maintained by the activation of telomerase, which causes continuous cell division and proliferation in many carcinomas. A catalytic reverse transcriptase protein (TERT) encoded by the TERT gene plays a critical role in the activation of telomerase. We performed a molecular and pathological analysis of the TERT against three different peripheral T-cell lymphoma (PTCL) subtypes: PTCL, not otherwise specified (PTCL-NOS), angioimmunoblastic T-cell lymphoma (AITL), and adult T-cell leukemia/lymphoma (ATLL). Immunohistochemical analysis demonstrated TERT expression in 31% of AITL, 11% of PTCL-NOS, and 5% of ATLL. Among them, AITL frequently showed high TERT expression with statistical significance. TERT promoter mutation analysis and genomic copy number evaluation were performed. TERT promoter mutation was observed in two cases of PTCL-NOS (2/40) and not in other PTCLs. Genome copy number amplification was detected in 33% of PTCL-NOS, 33% of AITL, and 50% of ATLL cases. We evaluated the relationship between the analyzed TERT genomic abnormalities and protein expression; however, no apparent relationship was observed. Furthermore, immunostaining showed TERT expression in the PTCL cytoplasm, suggesting the existence of mechanisms other than the maintenance of telomere length. Statistical analysis of the effect of TERT expression on the prognosis in PTCL cases revealed that TERT expression tended to have a poor prognosis in PTCL-NOS. Since TERT expression was not an independent factor in multivariate analysis, further research will be needed to clarify the poor prognosis of PTCL-NOS in TERT expression.

Comprehensive genomic analysis identifying heterogeneity in peripheral T-cell lymphoma.

Peripheral T-cell lymphoma (PTCL) is a heterogeneous entity generally with a poor prognosis. Recent genomic analyses have characterized genomic alterations and described gene expression profiling and epigenetic mechanisms in PTCL, leading to reveal molecular pathophysiology in detail. One of several important findings is that heterogeneities exist in both the disease and in individuals. Among PTCL subtypes, adult T-cell leukemia/lymphoma (ATLL) and peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS) are common in Japan. ATLL is an incurable T-cell malignancy induced by human T-cell lymphotropic virus type 1 (HTLV-1). The global genomics of ATLL can be summarized as alterations involving T-cell receptor (TCR) signaling and immune escape mechanisms. This highlights the fact that ATLL is a viral-mediated T-cell malignancy. Interestingly, several previous studies have found that the genomics of ATLL differ according to geographical region and age at diagnosis, suggesting disease heterogeneity, though they share HTLV-1 infection as initial disease hit. Clonal expansion of the cells acquired by somatic mutations in ATLL-related genes is identified in a part of HTLV-1 carriers who developed ATLL later. The risk for ATLL may be updated based on findings in detail. PTCL-NOS is a heterogeneous disease type of T-cell lymphoma that does not correspond to any other type of PTCL. Several studies have stratified PTCL-NOS according to transcriptional, genomic, microenvironmental, and clinical aspects. These kinds of analysis from multiple aspects are useful to understand the heterogeneous group. These efforts will help guide suitable translational research to target PTCL.

Human T-cell lymphotropic virus HBZ and tax mRNA expression are associated with specific clinicopathological features in adult T-cell leukemia/lymphoma.

Adult T-cell leukemia/lymphoma (ATLL) is caused by human T-cell leukemia virus type 1 (HTLV-1). HTLV-1-associated mRNA, including HBZ and tax, is deeply involved in the pathogenesis of ATLL. Using 88 ATLL tissue samples, we performed in situ mRNA analysis of HBZ and tax, and investigated its association with clinicopathological characteristics of ATLL. The median value of HBZ signals (/1000 ATLL cells) was 795.2 (range: 0.4-4013.1) and of tax signals (/1000 ATLL cells) was 5.1 (range: 0.1-891.2). The low-expression HBZ group displayed significant increase in the number of skin lesion (P = 0.0283). The high-expression tax group displayed significant increase in the number of PD-1-positive tumor-infiltrating lymphocytes (P < 0.0001). In addition, we identified patients with very high-expression of tax signals (400 or more signals/1000 ATLL cells). These patients displayed significant reductions in the expression of HLA class I (P = 0.0385) and ß2M (P = 0.0124). Moreover, these patients displayed significantly poor overall survival (median survival time [MST] 7.7 months, 95% confidence interval [CI] [4.7-NA]), compared with the survival in patients with less than 400 tax signals (MST 22.6 months, 95% CI [13.7-41.7]) (P = 0.0499). These results suggest that Tax-mediated treatment of ATLL should be performed carefully in the high-expression tax group. More detailed studies could elucidate the clinicopathological significance of HBZ and tax mRNA expressions in ATLL.

TACC3 expression as a prognostic factor in aggressive types of adult T-cell leukemia/lymphoma patients.

INTRODUCTION: Adult T-cell leukemia/lymphoma (ATLL) is a malignant peripheral T-cell neoplasm associated with human T-cell leukemia virus type-1 (HTLV-1). The acute and lymphoma subtypes are regarded as aggressive ATLLs, and the overall survival (OS) of patients remains poor. Transforming acidic coiled-coil-containing protein 3 (TACC3) regulates microtubules, which are associated with cancer-related proteins overexpressed in various cancers. Such a relationship has not been reported in hematopoietic tumors, including ATLL. METHODS: We examined tissue microarrays of histological samples from 92 cases of aggressive ATLL and assessed clinical features, including TACC3 protein expression levels. RESULTS: Compared with TACC3-low, TACC3-high ATLL patients were significantly older (P < .001), with a tendency toward pleomorphic variant over other morphological classifications (P = .019). TACC3-high patients (median survival time [MST] 10.6 months, confidence interval [CI] [6.27-15.6]) had poorer OS compared to TACC3-low patients (MST 20 months, CI [9.43-38.5]) (P = .0168). Moreover, multivariate analysis on TACC3 expression levels suggests that TACC3-high is an independent significant prognostic factor (HR, 1.700; 95% CI, 1.037-2.753; P = .0355). CONCLUSION: Certain drugs that inhibit TACC3-overexpressing neoplastic cells are used clinically. Further studies might highlight a key role for TACC3 in the oncogenesis and progression of ATLL.

RHOA mutation in follicular T-cell lymphoma: Clinicopathological analysis of 16 cases.

Follicular T-cell lymphoma (FTCL) is considered to originate from follicular helper T-cell (Tfh) cells. Angioimmunoblastic T-cell lymphoma (AITL) and peripheral T-cell lymphomas with the Tfh phenotype, derived from Tfh cells, often harbor RHOA G17V mutation. We investigated whether RHOA mutations affect the clinicopathological features of FTCL. We performed deep sequencing and Sanger sequencing for RHOA exon 2 in 16 cases of FTCL. Nine cases showed RHOA mutations, including eight with c.G50T, p.Gly17Val and one with c.G50A, p.Gly17Glu, c.A52G, p.Lys18Glu, c.T102C, p.Tyr34Tyr and c.G145T, p.Asp49Tyr. Compared to the RHOA mutation-negative group, the RHOA mutation-positive group had a higher tendency for B-immunoblasts (P = 0.06), the AITL component (P = 0.09), and higher positive rate for CD10 (P = 0.09) and BCL6 (P = 0.09), and a significantly higher positive rate for CXCL13 (P = 0.04). Although not statistically significant, the RHOA mutation-positive group showed higher values for almost all characteristic AITL features. There was no significant difference in overall survival between RHOA mutation-positive and -negative groups. The RHOA mutation may play an important role in clinicopathological characteristics and lymphomagenesis of FTCL. A more detailed investigation is needed to highlight the importance of RHOA mutations in FTCL.