Multimodal Gated Mixture of Experts Using Whole Slide Image and Flow Cytometry for Multiple Instance Learning Classification of Lymphoma

In this study, we present a deep-learning-based multimodal classification method for lymphoma diagnosis in digital pathology, which utilizes a whole slide image (WSI) as the primary image data and flow cytometry (FCM) data as auxiliary information. In pathological diagnosis of malignant lymphoma, FCM serves as valuable auxiliary information during the diagnosis process, offering useful insights into predicting the major class (superclass) of subtypes. By incorporating both images and FCM data into the classification process, we can develop a method that mimics the diagnostic process of pathologists, enhancing the explainability. In order to incorporate the hierarchical structure between superclasses and their subclasses, the proposed method utilizes a network structure that effectively combines the mixture of experts (MoE) and multiple instance learning (MIL) techniques, where MIL is widely recognized for its effectiveness in handling WSIs in digital pathology. The MoE network in the proposed method consists of a gating network for superclass classification and multiple expert networks for (sub)class classification, specialized for each superclass. To evaluate the effectiveness of our method, we conducted experiments involving a six-class classification task using 600 lymphoma cases. The proposed method achieved a classification accuracy of 72.3%, surpassing the 69.5% obtained through the straightforward combination of FCM and images, as well as the 70.2% achieved by the method using only images. Moreover, the combination of multiple weights in the MoE and MIL allows for the visualization of specific cellular and tumor regions, resulting in a highly explanatory model that cannot be attained with conventional methods. It is anticipated that by targeting a larger number of classes and increasing the number of expert networks, the proposed method could be effectively applied to the real problem of lymphoma diagnosis.

Comprehensive genetic profiling reveals frequent alterations of driver genes on the X chromosome in extranodal NK/T-cell lymphoma

Extranodal NK/T-cell lymphoma (ENKTCL) is an Epstein-Barr virus (EBV)-related neoplasm with male dominance and a poor prognosis. A better understanding of the genetic alterations and their functional roles in ENKTCL could help improve patient stratification and treatments. Here, we performed comprehensive genetic analysis of 177 ENKTCL cases to delineate the landscape of mutations, copy number alterations (CNAs), and structural variations, identifying 34 driver genes including six previously unappreciated ones, namely HLA-B, HLA-C, ROBO1, CD58, POT1, and MAP2K1. Among them, CD274 (24%) was the most frequently altered, followed by TP53 (20%), CDKN2A (19%), ARID1A (15%), HLA-A (15%), BCOR (14%), and MSN (14%). Chromosome X (chrX) losses were the most common arm-level CNAs in females (~40%), and alterations of four X-linked driver genes (MSN, BCOR, DDX3X, and KDM6A) were more frequent in males and females harboring chrX losses. Among X-linked drivers, MSN was the most recurrently altered, and its expression was lost in approximately one-third of cases using immunohistochemical analysis. Functional studies of human cell lines demonstrated that MSN disruption promoted cell proliferation and NF-κB activation. Moreover, MSN inactivation increased sensitivity to NF-κB inhibition in vitro and in vivo. In addition, recurrent deletions were observed at the origin of replication in the EBV genome (6%). Finally, by integrating the 34 drivers and 19 significant arm-level CNAs, non-negative matrix factorization and consensus clustering identified two molecular groups with different genetic features and prognosis irrespective of clinical prognostic factors. Together, these findings could help improve diagnostic and therapeutic strategies in ENKTCL.

Increased expression of leucine-rich α-2 glycoprotein 1 as a predictive biomarker of favorable progression-free survival in meningioma

Most meningiomas, which are frequent central nervous system tumors, are classified as World Health Organization (WHO) grade 1 because of their slow-growing nature. However, the recurrence rate varies and is difficult to predict using conventional histopathological diagnoses. Leucine-rich α-2 glycoprotein 1 (LRG1) is involved in cell signal transduction, cell adhesion, and DNA repair and is a predictive biomarker in different malignant tumors; however, such a relationship has not been reported in meningiomas. We examined tissue microarrays of histological samples from 117 patients with grade 1 and 2 meningiomas and assessed their clinical and pathological features, including expression of LRG1 protein. LRG1-high meningiomas showed an increased number of vessels with CD3-positive cell infiltration (P = 0.0328) as well as higher CD105-positive vessels (P = 0.0084), as compared to LRG1-low cases. They also demonstrated better progression-free survival (hazard ratio [HR] 0.11, 95% confidence interval [CI] 0.016-0.841) compared to LRG1-low patients (P = 0.033). Moreover, multivariate analysis indicated that high LRG1 expression was an independent prognostic factor (HR, 0.13; 95% CI, 0.018-0.991; P = 0.049). LRG1 immunohistochemistry may be a convenient tool for estimating the prognosis of meningiomas in routine practice. Further studies are required to elucidate the key role of LRG1 in meningioma progression.

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 features of adult T-cell leukemia/lymphoma with T-follicular helper phenotype

AIMS

T-follicular helper (TFH) cells are effector T-cells that are crucial for B-cell selection and differentiation. T-cell lymphomas derived from TFH cells have distinct characteristics. Additionally, in the World Health Organization (WHO) classification 5th edition, three lymphomas were introduced as independent disease entities with TFH cell origin. We aimed to investigate the clinicopathological features of adult T-cell leukemia/lymphoma (ATLL) with a TFH phenotype (TFHP).

METHODS AND RESULTS

We performed TFH immunohistochemistry analysis of five biomarkers for the biopsy specimen, with TFHP being indicated by a positive result for more than two markers. Among 75 cases of ATLL, 37.3% of them showed TFHP. Compared with cases of ATLL without TFHP, cases of ATLL with TFHP showed higher C-reactive protein levels (p = 0.0219) and increased high endothelial venule proliferation (p = 0.024). However, there were no significant between-group differences in overall survival as well as other clinical and morphological findings. Furthermore, there was no significant between-group difference in TFH markers and FOXP3 expression.

CONCLUSION

Some patients with ATLL may present a TFHP, which should not preclude the diagnosis of ATLL. Although presenting a TFHP does not affect prognosis, it is important to identify cases of ATLL with a TFHP since it may inform future treatment strategies.

EBV+ nodal T/NK-cell lymphoma associated with clonal hematopoiesis and structural variations of the viral genome

Epstein-Barr virus (EBV)+ nodal T- and NK-cell lymphoma (EBV+ nPTCL) is a peripheral T-cell lymphoma (PTCL) that presents as a primary nodal disease with T-cell phenotype and EBV harboring on tumor cells. To date, the genetic aspect of EBV+ nPTCL has not been fully investigated. In this study, whole-exome and/or genome sequencing was performed on 22 cases of EBV+ nPTCL. TET2 (68%) and DNMT3A (32%) were observed to be the most frequently mutated genes whose presence was associated with poor overall survival (p = 0.004). The RHOA p.Gly17Val mutation was identified in two patients who had TET2 and/or DNMT3A mutations. In four patients with TET2/DNMT3A alterations, blood cell-rich tissues (bone marrow [BM] or spleen) were available as paired normal samples. Three out of these four cases had at least one identical TET2/DNMT3A mutation in the BM or spleen. Additionally, the whole part of the EBV genome was sequenced and structural variations (SVs) were found frequent among the EBV genomes (63%). The most frequently identified type of SV was deletion. In one patient, four pieces of human chromosome 9, including PD-L1 were identified to be tandemly incorporated into the EBV genome. The 3'-untranslated region of PD-L1 was truncated, causing a high-level of PD-L1 protein expression. Overall, the frequent TET2 and DNMT3A mutations in EBV+ nPTCL seem to be closely associated with clonal hematopoiesis and, together with the EBV genome deletions, may contribute to the pathogenesis of this intractable lymphoma.

Co-expression of regulatory B-cell markers, transforming growth factor β 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 β (TGF-β) 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-β 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-β 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-β 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.

The first autopsy case of Epstein-Barr virus-positive marginal zone lymphoma that deteriorated after COVID-19 vaccination

This is the first autopsy case of Epstein-Barr virus-positive marginal zone lymphoma (EBV + MZL) with an other iatrogenic immunodeficiency-associated lymphoproliferative disorders (LPD) (methotrexate [MTX]-associated LPD) that deteriorated after the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine. This case had a unique immunophenotype. A 71-year-old female patient with rheumatoid arthritis receiving MTX presented with fatigue 1 week after the SARS-CoV-2 vaccination. She was hospitalized due to hepatorenal dysfunction and pancytopenia. Computed tomography revealed systemic lymphadenopathy. Her physical condition deteriorated, and the patient died. The autopsy revealed systemic lymphadenopathy comprising medium-sized atypical lymphocytes and scattered Hodgkin/Reed-Sternberg (H/RS)-like cells. An immunohistochemical examination showed that atypical lymphocytes were positive for CD79a and MUM-1 and some were positive for CD20 and IRTA-1. H/RS-like cells were immunoreactive for CD30 and CD15 and ringed by T cells. Both cell types were positive for EBV-encoded small RNA. The majority of H/RS-like cells were positive for CD20, whereas a small number of CD3-positive cells were admixed. We herein presented the first autopsy case of EBV + MZL that deteriorated after the SARS-CoV-2 vaccination.

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.

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.

18F-FDG PET/CT imaging of IgG4-producing MALT lymphoma with multiple site involvement

18F-FDG PET/CT is regarded as a modality utilized for the purpose of lesion localization, staging and assessment of treatment response in patients with lymphoma. However, it is difficult that we diagnose among multifocal lymphoma, IgG4-related disease (IgG4-RD), or a combination of both conditions when confronted with multiple sites of 18F-FDG uptake with heightened serum IgG4 levels. We present a case of a 72-year-old male who was suspected of Sjögren's syndrome based on symptoms of xerostomia accompanied by swelling of the bilateral upper eyelid and salivary glands. Following a diagnostic biopsy that revealed mucosa-associated lymphoid tissue (MALT) lymphoma as a possible finding, 18F-FDG PET/CT was conducted, which demonstrated multiple sites of 18F-FDG accumulation. While multifocal MALT lymphoma was initially suspected, the coexistence of IgG4-RD could not be definitively ruled out due to the elevated serum IgG4 levels. Subsequent histopathological and immunohistochemical examinations confirmed the diagnosis of IgG4-producing MALT lymphoma. After receiving systemic therapy with rituximab, the swelling of the bilateral upper eyelid and parotid glands resolved upon visual examination, and the serum IgG4 levels returned to within the normal range in a few months. No new lesions were detected during the subsequent follow-up examinations conducted over a period of 3 years.

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.

Co-stimulatory and immune checkpoint molecules are important in the tumor microenvironment of Hodgkin-like adult T-cell leukemia/lymphoma

Not available.

Angioimmunoblastic T-Cell Lymphoma after Treatment of Classic Hodgkin Lymphoma: A Case Report

We report a case of a 24-year-old man who developed angioimmunoblastic T-cell lymphoma (AITL) after treatment for refractory lymphocyte-rich classic Hodgkin lymphoma (LR-CHL). This patient was treated with the BV+AVD (brentuximab vedotin, doxorubicin, vinblastine, and dacarbazine) protocol for LR-CHL but progressed before completing chemotherapy. The pathological imaging showed the typical findings of LR-CHL at the first onset and first progression. Rescue chemotherapy and high-dose chemotherapy combined with autologous hematopoietic stem cell transplantation (AHSCT) were performed for refractory LR-CHL, and complete remission was achieved. However, the recurrence was suspected 6 months after AHSCT. The pathological findings of the lymph node biopsy at this time were different from those of the previous two lymph node biopsies, demonstrating findings of AITL. The finding of the immunohistochemical staining and polymerase chain reaction results supported the diagnosis. Although it has been reported that the risk for the development of non-Hodgkin lymphoma after treatment for Hodgkin lymphoma is increased, most are B-cell lymphomas, and few cases of AITL have been reported. AITL is a type of peripheral T-cell lymphoma that generally occurs in middle-aged and elderly people and that rarely occurs in young people. Here, we were able to make an accurate diagnosis by performing re-examination even when recurrence of LR-CHL was suspected. As there are no detailed case reports of AITL developing into secondary non-Hodgkin lymphoma, here we report on an identified case.

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.

Intratumoral thrombosis as a histological biomarker for predicting epidermal growth factor receptor alteration and poor prognosis in patients with glioblastomas

PURPOSE

Intratumoral thrombosis is a specific finding in glioblastomas and considered the origin of palisading necrosis. Its distribution and contribution to the glioblastoma pathophysiology and systemic thrombosis are obscure, although deep vein thrombosis is a common complication in glioblastoma cases.

METHODS

Clinicopathological and genetic analyses were performed on 97 glioblastoma tissue specimens to elucidate the role of thrombotic events and associated molecular abnormalities.

RESULTS

Morphologically, intratumoral thrombosis was observed more frequently in vessels composed of single-layered CD34-positive endothelium and/or αSMA-positive pericytes in the tumor periphery, compared to microvascular proliferation with multi-channeled and pericyte-proliferating vessels in the tumor center. Intratumoral thrombosis was significantly correlated with the female sex, high preoperative D-dimer levels, and epidermal growth factor receptor (EGFR) amplification. The presence of one or more thrombi in 20 high-power fields was a predictive marker of EGFR amplification, with a sensitivity of 81.5% and specificity of 52.6%. RNA sequencing demonstrated that the group with many thrombi had higher EGFR gene expression levels than the group with few thrombi. The tumor cells invading along the vessels in the tumor periphery were positive for wild-type EGFR but negative for EGFRvIII, whereas the cells around the microvascular proliferation (MVP) in the tumor center were positive for both wild-type EGFR and EGFRvIII. Intratumoral thrombosis is an independent poor prognostic factor.

CONCLUSIONS

Aberrant but exquisitely regulated EGFR can induce thrombosis in non-MVP vessels in the tumor invasion area and then promote palisading necrosis, followed by hypoxia, abnormal angiogenesis, and further tumor cell invasion.

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.

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.

Integrated genetic and clinical prognostic factors for aggressive adult T-cell leukemia/lymphoma

The prognosis of aggressive adult T-cell leukemia/lymphoma (ATL) is poor, and allogeneic hematopoietic stem-cell transplantation (allo-HSCT) is a curative treatment. To identify favorable prognostic patients after intensive chemotherapy, and who therefore might not require upfront allo-HSCT, we aimed to improve risk stratification of aggressive ATL patients aged.

The case of T-ALL presenting with NK phenotype after COVID-19 vaccination

NK-lymphoblastic leukemia/lymphoma (NK-LL) is an extremely rare hematopoietic tumor consisting of natural killer (NK) precursor cells, and their lineage overlaps with T-cells, making it challenging to diagnose. COVID-19 vaccination is recommended for people with a risk of aggravation such as cancer-bearing patients, including hematopoietic tumors. We present a 55-year-old man who had cervical lymph node swelling post vaccination for COVID-19. Hematological malignancy was suspected due to the presence of atypical lymphoid cells with an elevated IL-2R in laboratory data. Tumor cells were positive for CD7, CD56, cyCD3, and terminal deoxynucleotidyl transferase (TdT) evidenced through flow cytometry of the bone marrow and the lymph node. The histopathological findings showed monotonous tumor cell proliferation, the cells being positive for CD3 and TdT in the bone marrow and they were positive for CD3, TdT, and CD56 in lymph node. Even though these findings suggested NK-LL, clonal T-cell receptor (TCR) β gene rearrangement by Southern blot hybridization was observed in the bone marrow. TCRβ rearrangement led to the final diagnosis of T-cell lymphoblastic leukemia (T-ALL). The causal relationship between COVID-19 vaccination and carcinogenesis is not clear, and more cases need to be studied in order to elucidate the relationship between the two factors.

Transformer-based personalized attention mechanism for medical images with clinical records

In medical image diagnosis, identifying the attention region, i.e., the region of interest for which the diagnosis is made, is an important task. Various methods have been developed to automatically identify target regions from given medical images. However, in actual medical practice, the diagnosis is made based on both the images and various clinical records. Consequently, pathologists examine medical images with prior knowledge of the patients and the attention regions may change depending on the clinical records. In this study, we propose a method, called the Personalized Attention Mechanism (PersAM) method, by which the attention regions in medical images according to the clinical records. The primary idea underlying the PersAM method is the encoding of the relationships between medical images and clinical records using a variant of the Transformer architecture. To demonstrate the effectiveness of the PersAM method, we applied it to a large-scale digital pathology problem involving identifying the subtypes of 842 malignant lymphoma patients based on their gigapixel whole-slide images and clinical records.

[Methotrexate-related lymphoproliferative disease showing different histological findings at recurrence]

A 55-year old female patient was treated with methotrexate (MTX) and infliximab (IFX) for rheumatoid arthritis (RA). She experienced unknown fever, generalized lymphadenopathy, and liver tumors. Histological examination of the inguinal lymph node and a liver tumor resulted in the pathological diagnosis of classic Hodgkin lymphoma, with many Reed-Sternberg cells with the positivity of Epstein-Barr virus (EBV). She was diagnosed with MTX-related lymphoproliferative disorders (MTX-LPDs). She received chemotherapy after the cessation of MTX and IFX and achieved complete remission. RA showed recurrence after a while, and she was treated with steroids or other drugs. Six years after the chemotherapy, she experienced low-grade fever and anorexia. Whole computed tomography images showed an appendix tumor and enlargement of the surrounding lymph nodes. Appendectomy with the radical lymph nodes dissection was performed. The pathological diagnosis was diffuse large B-cell lymphoma, resulting in the clinical diagnosis of the relapse of MTX-LPD. EBV was negative at this point. The pathological findings of MTX-LPD may change at relapse; thus, biopsy should be considered when the relapse of MTX-LPD is suggested.

Combined use of pathological and genomic alteration analyses for the diagnosis of gray zone lymphoma

Histiocytic sarcoma (HS) is a rare malignancy showing morphologic and immunophenotypic features of histiocytes. HS has morphologic overlap with many other diseases, including various kinds of lymphomas. Gray zone lymphoma (GZL) is a rare B-cell lymphoma subtype characterized by overlapping features between diffuse large B-cell lymphoma and classic Hodgkin lymphoma. The histologic overlap with other diverse diseases of HS and the pathological diversity of GZL make it difficult to render a diagnosis. A 44-year-old woman who was initially diagnosed with HS was diagnosed with GZL after reexamination, including a genetic alteration test. After 6 cycles of brentuximab vedotin, doxorubicin, vinblastine, and dacarbazine, she achieved a complete response. Genomic alteration assessment may be useful for the accurate diagnosis of malignant lymphomas, which are difficult to diagnose, such as GZL.

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. This article is protected by copyright. All rights reserved.

Lymphoid and myeloid proliferative disorders associated with inflammatory bowel disease: A clinicopathological study of 15 cases

Lymphoproliferative disorder (LPD) can occur in patients with inflammatory bowel disease (IBD) such as ulcerative colitis (UC) and Crohn's disease (CD). On rare occasion, patients with IBD develop myeloid neoplasms; however, the frequency and clinicopathological features of IBD-associated lymphoid and myeloid proliferative disorder (LMPD) in Japanese patients is still unclear. In this study, we reviewed 2474 Japanese patients with IBD, and found that LMPD occurred in 12 (0.5%) patients with UC (n=7) or CD (n=5). Together with an additional 3 cases, we analyzed a total of 15 cases of LMPD for clinicopathological and histological features. Based on the status of using immunosuppressants such as biologics and immunomodulators, Epstein-Barr virus (EBV) infection, and histopathology, the 15 cases were classified into the Group I (high-grade LPD; n=7), Group II (low-grade LPD; n=5), and Group III (myeloid neoplasms; n=3). Most patients in Group I were undergoing strong immunosuppressive therapy, and the LPD lesions corresponded to high-grade B-cell or T/NK-cell lymphoma often with EBV infection. Discontinuation of immunosuppressive drugs alone did not resolve these LPDs; Group I patients required chemotherapy, and eventually 4 of them (57%) died of the tumor. Most cases in Group II were low-grade B-cell lymphoma without EBV infection and had an indolent clinical course with excellent prognosis. All patients in Group III developed acute myeloid leukemia (AML) during the course of CD. Two (67%) of these patients died of AML. Our study suggests that IBD-associated LMPD is very rare, but can follow an aggressive clinical course.

Neutron flat-panel detector using In-Ga-Zn-O thin-film transistor

Neutron imaging is a powerful tool for observing the internal structure of an object without destroying the object. Neutron imaging (neutron radiography) is a prominent application of neutrons but still requires significant improvements, for example, in sensitivity, resolution, radiation hardness, and handling of neutron imaging detectors. This paper presents the development and the first neutron imaging results of a neutron flat-panel detector (nFPD) based on an In-Ga-Zn-O (IGZO) thin-film transistor (TFT)/photodiode array coupled with a LiF/ZnS scintillator sheet. Direct photo-coupling to the scintillator increases the light collection efficiency. Moreover, unlike lens-coupled neutron cameras, the proposed detector is compact and easy to handle. Owing to the high off-state resistance of IGZO TFTs, their leakage current is lower than that of conventional TFTs, enabling the IGZO TFTs to hold an accumulated charge for a longer period of time and allowing longer exposure times for imaging. This would be a powerful feature for imaging at compact neutron sources with limited flux. This paper reports on the first neutron imaging results with an IGZO nFPD, its performance evaluation, and a demonstration of three-dimensional computed tomography with neutrons.

Intestinal T-Cell Lymphoma With Lung and Lymph Node Involvement at Relapse

Patients with intestinal T-cell lymphomas (ITLs) usually present with perforation of the small intestine and colon at diagnosis. At relapse or in the advanced stage, ITLs involve in other extranodal sites, but biopsy-proven lung involvement has been rarely reported. A 76-year-old male presented with sudden-onset abdominal pain, which was found to be caused by the perforation of colon. Emergency operation was carried out, and histopathological examination of the resected colon led to the diagnosis of ITL, not otherwise specified (NOS). He achieved complete metabolic remission (CMR) after eight courses of CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisolone) chemotherapy. Two months later, computed tomography showed infiltration and ground-glass opacity in the left pulmonary area in addition to the enlargement of mediastinal and left subclavian lymph nodes, although he did not complain of any pulmonary symptoms. Histopathological findings of the biopsied samples from the pulmonary area were consistent with relapsed ITL, NOS. He achieved CMR after three courses of GDP (gemcitabine, dexamethasone, and cisplatin) chemotherapy; but 1 month after the completion of GDP chemotherapy, he relapsed again with involvement of multiple lymph nodes, not in the pulmonary area. He died owing to the progression of disease. This is the third case of ITLs with lung involvement. Active biopsy should be performed when pulmonary nodules, infiltration, or ground-glass opacity are found in ITLs. A regimen for salvage chemotherapy specifically for ITLs is not yet established, and GDP chemotherapy may be an alternative option for relapsed ITLs in addition to new agents, such as romidepsin and pralatrexate.

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.

The first case of methotrexate-associated lymphoproliferative disorder presenting as follicular T-cell lymphoma

This is the first case of follicular T-cell lymphoma (FTCL) presenting as methotrexate-associated lymphoproliferative disorders (MTX-LPDs). A 69-year-old man treated rheumatoid arthritis with methotrexate presented with cervical swelling, hoarseness and fever. Imaging studies revealed multiple lymphadenopathy and lymphoma was suspected. Lymph node biopsy was performed to confirm the diagnosis. Pathologically, the lymph node was composed of atypical lymphocytes with a follicular growth pattern and area of necrosis. Immunohistochemical examination showed the atypical lymphocytes were positive for CD3, CD4, programmed cell death protein 1, and inducible T-cell co-stimulator. These findings are consistent with FTCL. During hospitalization, the patient's fever subsided and cervical lymphadenopathy improved, probably due to discontinuation of MTX. Here we presented the first case of FTCL presenting as MTX-LPDs. The T-cell phenotype MTX-LPDs are relatively rare and accounts for only 3.4%-6.3% of all MTX-LPD cases. Therefore, detailed clinicopathological features have not been clarified sufficiently. It is hoped that similar cases should be accumulated and studied to better understand the clinical and pathological features of this condition.

High numbers of programmed cell death-1-positive tumor infiltrating lymphocytes correlate with early onset of post-transplant lymphoproliferative disorder

Post-transplant lymphoproliferative disorder (PTLD) is a life-threatening complication of transplantation. In addition to reactivation of Epstein-Barr virus in immunocompromised patients, impaired tumor immunity is suggested to be a risk factor for PTLD. However, it remains unclear whether immune suppressive tumor-infiltrating lymphocytes (TILs) correlate with the occurrence or prognosis of PTLD. We analyzed TILs in 26 patients with PTLD to elucidate the clinicopathological significance of the expression of PD-1 and FoxP3, which are associated with exhausted T-cells and regulatory T-cells (Tregs), respectively. Numbers of PD-1⁺ TILs in the PTLD specimens were significantly higher in patients who developed PTLD early after transplantation (P = 0.0040), while numbers of FoxP3⁺ TILs were not (P = 0.184). There was no difference in overall response rate regardless of the expression of PD-1 or FoxP3. FoxP3^high patients tended to have a shorter time to progression compared with FoxP3^low patients, especially in the case of FoxP3^high patients with diffuse large B-cell lymphoma-subtype PTLD (P = 0.011), while PD-1^high patients did not. These results suggest that T-cell exhaustion may be mainly associated with PTLD development, while immune suppression by Tregs may be dominant in enhanced progression of PTLD following disease occurrence.

Outcomes of methotrexate-associated lymphoproliferative disorders in rheumatoid arthritis patients treated with disease-modifying anti-rheumatic drugs

Recently, the use of targeted synthetic or biological disease-modifying anti-rheumatic drugs (ts/bDMARDs) in addition to conventional synthetic (cs)DMARDs including methotrexate (MTX) for rheumatoid arthritis (RA) has increased. However, whether ts/bDMARDs are associated with the development and clinicopathological features of MTX-associated lymphoproliferative disorder (MTX-LPD) in patients with RA remains unknown. Therefore, we evaluated the clinical outcomes of 121 patients with MTX-LPD. Results showed that prior use of ts/bDMARDs was not associated with the different histopathological subtypes of MTX-LPD. Patients with polymorphic-type LPD had a better event-free survival than those with diffuse large B-cell lymphoma (DLBCL), classical Hodgkin lymphoma and peripheral T-cell lymphoma. The pathological subtype of lymphoma could predict the clinical outcome of MTX-LPD. In patients with DLBCL, the use of tumour necrosis factor-alpha (TNF-α) inhibitors prior to MTX-LPD onset was associated with a higher non-relapse mortality. Further, patients with RA previously treated with Janus kinase (JAK) inhibitors more commonly required chemotherapy than those treated with csDMARDs alone, indicating disease aggressiveness. Hence, special caution should be observed when managing patients with MTX-LPD previously treated with JAK or TNF-α inhibitors for RA.

DA-EPOCH-R therapy for high-grade B-cell lymphoma with MYC and BCL2 and/or BCL6 rearrangements in a patient with renal dysfunction

High-grade B-cell lymphoma with MYC and BCL2 and/or BCL6 rearrangements, also known as double-hit lymphoma, has been reported as refractory to R-CHOP therapy and requires more intensive regimens. However, intensive and safe regimens for patients with renal dysfunction are unknown. Herein, we report the successful use of DA-EPOCH-R therapy for double-hit lymphoma in a 64-year-old man with renal dysfunction. The patient had lymphoma-induced bilateral ureteral obstruction. Although renal dysfunction remained after removing the obstruction using R-CHOP therapy, we completed six cycles of DA-EPOCH-R therapy without any major adverse events. DA-EPOCH-R therapy may be a safe regimen for renal dysfunction patients.

Tumor microenvironment of adult T-cell leukemia/lymphoma

Adult T-cell leukemia/lymphoma (ATLL) is a malignancy caused by the human T-cell leukemia virus type 1. Aggressive ATLL is refractory to conventional chemotherapy and has a poor prognosis. Better therapeutic approaches, including cancer immunotherapy, are required to improve survival and prognosis. The genetic landscape of ATLL reveals frequent genetic alterations in genes associated with immune surveillance, including major histocompatibility complex (MHC) class I, CD58 antigen, and programmed cell death ligand 1. Clinicopathological investigations also revealed tumor immunity mechanisms in ATLL, including immune checkpoint molecules, MHC molecules, tumor-associated macrophages, and chemokines. However, the tumor microenvironment of ATLL remains complex because ATLL itself originates from T-cells, usually expressing regulatory T-cell markers. In this review, we discuss the recent literature describing the tumor microenvironment of ATLL.

Comparison of PD-L1 immunohistochemical assays and the significance of PD-L1 expression in thymoma

Thymoma is a relatively rare malignancy, which is categorized as thymic epithelial tumor but known as the most common pathology that is developed in the anterior mediastinum. Complete resection is recommended for localized tumors and usually favorable prognosis can be obtained. However, poor survival period has been reported in unresectable cases exhibiting extensive invasion or distant metastasis, as effective chemotherapeutic regimens are restrained. We previously assessed expression of programmed death ligand 1 (PD-L1) and programmed death 1 (PD-1) and discussed their prospective application in the immunotherapy of thymic epithelial tumors. After our publication, additional studies using reliable PD-L1 antibodies, which are currently administered to predict efficacy of PD-1/PD-L1 blockade therapy were performed and further characterized PD-L1 in thymoma. Herein, recent knowledge in relation to the significance of PD-L1 expression in thymoma is reviewed based on recent findings using qualified PD-L1 clones. Most studies coherently found high expression of PD-L1 on the cell membrane and cytoplasm of tumor epithelial cells in accordance with previous reports, which is a predictive marker for effectiveness of anti-PD-1/PD-L1 drugs, even when approved PD-L1 antibodies were employed. On the other hand, PD-L1 expression on tumor infiltrating immune cells remains to be sufficiently determined. High PD-L1 expression can be expected in cases with high grade histological subtypes, such as type B2/B3 thymomas, or those with advanced stages III or IV of the disease. Interestingly, the level of PD-L1 expression was found to be upregulated after chemotherapy compared with that before, which could be explained by immunogenic cell death. The prognostic impact of PD-L1 expression in thymoma might be found only when thymic carcinoma patients were excluded. Furthermore, it also could be identified when we analyzed thymomas completely resected, distinct from biopsy and incompletely resected cases.

Correction to: Programmed death 1 ligand (PD-L1) in solid cancers after allogeneic hematopoietic stem cell transplantation: a retrospective analysis by the Nagasaki Transplant Group

In the original publication of the article, the authors would like to alter the color of characters in the Supplemental Table 1 and 2.

The first reported case of primary extranodal counterpart of follicular T-cell lymphoma of submandibular gland

This is the first reported case of follicular T-cell lymphoma (FTCL) that primarily developed in the extranodal site of the right submandibular gland. An 86-year-old man was detected with a right cervical mass suspected to be malignant lymphoma during his physical examination. Imaging studies revealed that the mass was a submandibular gland tumor. The tumor was excised for diagnosis and treatment. Pathologically, the tumor was composed of densely aggregated lymphocytes with a follicular growth pattern. The immunohistochemical investigation showed that the lymphoma cells expressed CD3, CD4, programmed cell death protein 1, BCL6, chemokine (C-X-C motif) ligand 13, and BCL2. Staining of the follicular dendritic cell revealed its meshwork structure limited in the germinal center. Monoclonal rearrangement of the T-cell receptor was detected using polymerase chain reaction. These findings are consistent with the characteristics of FTCL. Here, we describe the first reported case of extranodal counterpart of FTCL of the submandibular gland. Accumulation and investigation of such extranodal cases is essential.

Benign mesenteric lipomatous tumor in a child: a case report and literature review

BACKGROUND

Lipomatous tumors are the most common type of soft-tissue tumors. Benign lipomatous tumors are lipomas and lipoblastoma. We herein report a case of benign mesenteric lipomatous tumor and the largest collection of known benign mesenteric lipomatous tumors in children in the literature.

CASE PRESENTATION

A 3-year-old girl presented with repeated dull abdominal pain and left abdominal mass swelling. On a physical examination, the child had a soft, moderately distended left abdomen that was not tender when palpated. Computed tomography and magnetic resonance imaging demonstrated a large fatty mass within the mesentery, measuring approximately 8 × 6 cm. The mass extended from the right upper quadrant to the lower pole of the kidneys. Laparotomy with resection of the mesenteric tumor was performed under general anesthesia. A well-capsuled tumor was a soft, yellow mass and found loosely attached to the mesenterium of the ileum. A histopathological examination demonstrated the lobular proliferation of mature adipocytes. Atypical lipoblasts were not seen. These features are compatible with benign lipomatous tumor, such as lipoma or lipoblastoma with maturation.

CONCLUSION

In conclusion, benign mesenteric lipomatous tumors tend to be large in size over 10 cm in longitudinal length. However, resection is well tolerated in the vast majority of cases with benign post-operative courses.

Cytokine-related genes play critical roles in extrafollicular growth of follicular lymphoma cells

Follicular lymphoma (FL) is a germinal center-derived B-cell lymphoma that is known to proliferate in the intrafollicular region. However, lymphoma cells can be identified in the extrafollicular regions, which are related to disease dissemination. We purified the intrafollicular and extrafollicular regions of FL cells by laser microdissection and conducted microarray analysis in order to characterize the gene expression profiles of FL cells from both regions. BCL2 and genes of germinal B-cell markers clearly separated intrafollicular and extrafollicular regions of reactive follicular hyperplasia, suggesting the adequacy of the current analysis. In FL cases, cytokine-related genes were significantly enriched in extrafollicular regions compared with those in the intrafollicular regions. In intrafollicular regions of FL, cell-cycle-related genes were enriched. We found that the FL cells in the extrafollicular region more strongly expressed IL3RA and CXCL12 than those of intrafollicular regions. The cytokines might be also derived from stroma cells in the extrafollicular regions, which may initiate activation and migration of the tumor cells to this region. Our results suggest that FL cell interaction with surrounding stroma cells plays an important role in the pathophysiology of FL and that such interactions should be a good target for therapy.

Clinicopathological analysis of immunohistochemical expression of CD47 and SIRPα in adult T-cell leukemia/lymphoma

The interaction of CD47 and signal-regulatory protein alpha (SIRPα) induces "don't eat me signal", leading suppression of phagocytosis. This signal can affect the clinical course of malignant disease. Although CD47 and SIRPα expression are associated with clinicopathological features in several neoplasms, the investigation for adult T-cell leukemia/lymphoma (ATLL) has not been well-documented. This study aimed to declare the association between CD47 and SIRPα expression and clinicopathological features in ATLL. We performed immunostaining on 73 biopsy samples and found that CD47 is primarily expressed in tumor cells, while SIRPα is expressed in non-neoplastic stromal cells. CD47 positive cases showed significantly higher FoxP3 (P = .0232) and lower CCR4 (P = .0214). SIRPα positive cases presented significantly better overall survival than SIRPα negative cases (P = .0132). SIRPα positive cases showed significantly HLA class I (P = .0062), HLA class II (P = .0133), microenvironment PD-L1 (miPD-L1) (P = .0032), and FoxP3 (P = .0229) positivity. In univariate analysis, SIRPα expression was significantly related to prognosis (Hazard ratio [HR] 0.470; 95% confidence interval [CI] 0.253-0.870; P = .0167], although multivariate analysis did not show SIPRα as an independent prognostic factor. The expression of SIRPα on stromal cells reflects activated immune surveillance mechanism in tumor microenvironment and induce good prognosis in ATLL. More detailed studies for gene expression or genomic abnormalities will disclose clinical and biological significance of the CD47 and SIRPα 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.

Differences in the immunosurveillance pattern associated with DNA mismatch repair status between right-sided and left-sided colorectal cancer

Tumor location and immunity play important roles in the progression of colorectal cancer (CRC). This study aimed to investigate the differences in the immunosurveillance pattern between right‐ and left‐sided CRC and analyze their association with clinicopathologic features, including mismatch repair (MMR) status. We included surgically resected stage II/III CRC cases and evaluated the immunohistochemical findings of HLA class I, HLA class II, programmed cell death‐ligand 1 (PD‐L1), PD‐1, CTLA‐4, CD3, CD4, CD8, TIA‐1, T‐bet, GATA3, RORγT, Foxp3, and CD163. A total of 117 patients were included in the analyses; of these, 30 and 87 had right‐ and left‐sided cancer, respectively. Tumor immunity varied according to the tumor location in the overall cohort. Analysis of the tumors excluding those with DNA mismatch repair (MMR) deficiency also revealed that tumor immunity differed according to the tumor location. In right‐sided colon cancer (CC), high expression of Foxp3 (P = .0055) and TIA‐1 (P = .0396) were associated with significantly better disease‐free survival (DFS). High CD8 (P = .0808) and CD3 (P = .0863) expression tended to have better DFS. Furthermore, in left‐sided CRC, only high PD‐L1 expression in the stroma (P = .0426) was associated with better DFS. In multivariate analysis, high Foxp3 expression in right‐sided CC was an independent prognostic factor for DFS (hazard ratio, 7.6445; 95% confidence interval, 1.2091‐150.35; P = .0284). In conclusion, the immunosurveillance pattern differs between right‐ and left‐sided CRC, even after adjusting for MMR deficiency.

Clinical utility of target capture-based panel sequencing in hematological malignancies: A multicenter feasibility study

Although next‐generation sequencing‐based panel testing is well practiced in the field of cancer medicine for the identification of target molecules in solid tumors, the clinical utility and clinical issues surrounding panel testing in hematological malignancies have yet to be fully evaluated. We conducted a multicenter prospective clinical sequencing study to verify the feasibility of a panel test for hematological tumors, including acute myeloid leukemia, acute lymphoblastic leukemia, multiple myeloma, and diffuse large B‐cell lymphoma. Out of 96 eligible patients, 79 patients (82%) showed potentially actionable findings, based on the clinical sequencing assays. We identified that genetic alterations with a strong clinical significance were found at a higher frequency in terms of diagnosis (n = 60; 63%) and prognosis (n = 61; 64%) than in terms of therapy (n = 8; 8%). Three patients who harbored a germline mutation in either DDX41 (n = 2) or BRCA2 (n = 1) were provided with genetic counseling. At 6 mo after sequencing, clinical actions based on the diagnostic (n = 5) or prognostic (n = 3) findings were reported, but no patients were enrolled in a clinical trial or received targeted therapies based on the sequencing results. These results suggest that panel testing for hematological malignancies would be feasible given the availability of useful diagnostic and prognostic information. This study is registered with the UMIN Clinical Trial Registry (UMIN000029879, multiple myeloma; UMIN000031343, adult acute myeloid leukemia; UMIN000033144, diffuse large B‐cell lymphoma; and UMIN000034243, childhood leukemia).

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.

Combination of CD47 and signal-regulatory protein-α constituting the "don't eat me signal" is a prognostic factor in diffuse large B-cell lymphoma

The interaction between CD47 and signal‐regulatory protein‐α (SIRPα) inhibits phagocytosis, thus affecting the clinical outcomes of neoplastic diseases. Although CD47 upregulation is associated with poor prognosis in several malignancies, the effect of SIRPα expression and its coexpression with CD47 remains unclear. This study aimed to investigate the clinicopathologic effect of CD47 and SIRPα expression in diffuse large B‐cell lymphoma (DLBCL). Immunostaining of 120 biopsy samples showed that CD47 is primarily expressed in tumor cells, whereas SIRPα is expressed in nonneoplastic stromal cells, mostly macrophages. CD47^high cases showed higher MYC protein expression and lower MYC translocation. The SIRPα^high cases presented significantly shorter overall survival (OS) and progression‐free survival (PFS) than SIRPα^low cases in the activated B‐cell (ABC) subtype of DLBCL (P = .04 and P = .02, respectively). Both CD47^high and SIRPα^high presented significantly shorter OS and PFS than other cases among all DLBCL patients (P = .01 and P = .004, respectively), and the ABC type (P = .04 and P = .008, respectively) but not the germinal center B‐cell type. Both CD47^high and SIRPα^high yielded a constant independent prognostic value for OS and PFS in multivariate analysis (hazard ratio [HR], 2.93; 95% confidence interval [CI], 1.20‐7.43; P = .02; and HR, 2.87; 95% CI, 1.42‐5.85; P = .003, respectively). To the best of our knowledge, this is the first study to report that combinatorial CD47 and SIRPα expression is a potential independent prognostic factor for DLBCL. Evaluation of CD47 and SIRPα expression could be useful before CD47 blockade therapy.

Programmed death 1 ligand (PD-L1) in solid cancers after allogeneic hematopoietic stem cell transplantation: a retrospective analysis by the Nagasaki Transplant Group

Programmed death 1 ligand (PD-L1) is an immunomodulatory molecule expressed by cancer cells, and it has been widely demonstrated to inhibit host antitumor responses. The aim of the present study was to identify clinicopathological features associated with PD-L1 expression in the secondary solid cancers of patients after allogeneic hematopoietic stem cell transplantation. In this database of 530 patients who received allo-HSCT between 1990 and 2017, 15 developed solid cancers with a median interval of 3487 days after transplantation. Three patients had 2 different solid cancers. Eighteen solid cancer cases were identified. A multivariate analysis showed that chronic graft-versus-host disease (GVHD) was associated with an increased risk of solid cancer. The presence of chronic GVHD was observed in 8 out of 18 cases at the diagnosis of secondary malignancies. PD-L1 expression levels in cancers were significantly higher in patients with active chronic GVHD than in those without chronic GVHD (P = 0.020). Five cases of cancer that developed in the involved organs of chronic GVHD showed 30% or higher PD-L1 positivity. The present results revealed distinct PD-L1 expression in the secondary solid cancers of post-transplant patients with chronic GVHD.

Expression of GLUT1 in Pseudopalisaded and Perivascular Tumor Cells Is an Independent Prognostic Factor for Patients With Glioblastomas

Glioblastomas are highly aggressive brain tumors with a particularly poor prognosis. Glucose transporter-1 (GLUT1/SLC2A1), a uniporter that is expressed by various carcinomas and may be involved in malignant neoplasm glycometabolism, may also be related to prognosis in glioblastomas. GLUT1 is essential to central nervous system glycometabolism. To clarify the exact role of GLUT1 in glioblastoma, we assessed the expression and localization of GLUT1 in patient samples by immunohistochemistry and in situ RNA hybridization. This revealed that GLUT1 was mainly expressed on perivascular and pseudopalisaded tumor cell membranes. All samples expressed GLUT1 to some degree, with 30.8% showing stronger staining. On the basis of these data, samples were divided into high and low expression groups, although SLC2A1 mRNA expression was also higher in the high GLUT1 expression group. Kaplan-Meier survival curves revealed that high GLUT1 expression associated with lower overall survival (log-rank test, p = 0.001) and worse patient prognoses (p = 0.001). Finally, MIB-1 staining was stronger in high GLUT1 expression samples (p = 0.0004), suggesting a link with proliferation. We therefore hypothesize that GLUT1 expression in glioblastomas may enhance glycolysis, affecting patient prognosis. Examination of GLUT1 in patients with glioblastomas may provide a new prognostic tool to improve outcome.

Comprehensive immunohistochemical analysis of immune checkpoint molecules in adult T cell leukemia/lymphoma

Acute or lymphomatous type adult T cell leukemia/lymphoma (ATLL) is an aggressive hematopoietic malignancy with poor prognosis. We previously reported that programmed cell death ligand 1 (PD-L1) expression could predict ATLL outcomes. However, the roles of other immune checkpoint molecules remain largely unknown in ATLL. Our aim in this study was to explore the clinicopathological impacts of immune checkpoint molecules in ATLL. Immunohistochemistry was performed in 69 ATLL patients with antibodies against the following: PD-L1, programmed cell death ligand 2 (PD-L2), OX40, OX40 ligand (OX40L), CD137, CD137 ligand (CD137L), Galectin-9, T cell immunoglobulin mucin-3 (Tim-3), cytotoxic T lymphocyte associated protein-4 (CTLA-4), lymphocyte activating-3 (LAG-3), CD80, CD86, glucocorticoid-induced tumor necrosis factor receptor-related protein (GITR), GITR ligand (GITRL), and programmed death-1 (PD-1). Immune checkpoint molecules were variably expressed on neoplastic and/or microenvironmental cells. Expression of PD-1, OX40L, Galectin-9, and PD-L1 was nearly mutually exclusive on neoplastic cells, suggesting that immune checkpoint pathways differ in patients. Microenvironmental expression of PD-L1, OX40L, and Tim-3 was significantly associated with better overall survival (log-rank test; P =0.0004, 0.0394, and 0.0279, respectively). Univariate and multivariate analyses with clinical prognostic factors identified microenvironmental expression of PD-L1 and OX40L, and age (> 70 years) as significant prognostic factors. This is the first comprehensive analysis of ATLL immune checkpoint molecules. Our results may provide information on new therapeutic strategies in ATLL.

Dasatinib Is an Effective Treatment for Angioimmunoblastic T-cell Lymphoma

Recurrent hotspot (p.Gly17Val) mutations in RHOA encoding a small GTPase, together with loss-of-function mutations in TET2 encoding an epigenetic regulator, are genetic hallmarks of angioimmunoblastic T-cell lymphoma (AITL). Mice expressing the p.Gly17Val RHOA mutant on a Tet2-null background succumbed to AITL-like T-cell lymphomas due to deregulated T-cell receptor (TCR) signaling. Using these mice to investigate therapeutics for AITL, we found that dasatinib, a multikinase inhibitor prolonged their survival through inhibition of hyperactivated TCR signaling. A phase I clinical trial study of dasatinib monotherapy in 5 patients with relapsed/refractory AITL was performed. Dasatinib was started at a dose of 100 mg/body once a day and continued until days 10-78 (median day 58). All the evaluable patients achieved partial responses. Our findings suggest that AITL is highly dependent on TCR signaling and that dasatinib could be a promising candidate drug for AITL treatment. SIGNIFICANCE: Deregulated T-cell receptor signaling is a critical molecular event in angioimmunoblastic T-cell lymphoma and can be targeted with dasatinib.

[CD20-negative diffuse large B-cell lymphoma complicated by rheumatoid arthritis]

CD20 antigen is an important marker for diagnosis of B-cell neoplasms that is highly expressed on the surface of neoplastic B lymphocytes. Patients with rheumatoid arthritis (RA) have an increased risk of developing malignant lymphoma, of which diffuse large B-cell lymphoma (DLBCL) is the most common type. We report an unusual case of CD20-negative DLBCL complicated by rheumatoid arthritis. An 81-year old female presented with a left-sided cervical tumor, enlarged tonsil, and polyarticular pain. Pathological findings of the left tonsil showed proliferation of large atypical cells with irregular shaped nuclei. Most large cells were negative for CD3 and CD20. Additionally, these cells were positive for CD79a, BCL2, and MUM1, and negative for CD10, CD138, BCL6, PAX5, EBV-ISH, HHV8, and ALK.. Therefore, she was diagnosed with CD20-negative DLBCL complicated with RA and received dose-modified CHOP that achieved partial remission. Because CD20-negative DLBCL is rare, the identification of the clinicopathological features of this disease is urgently required.