Fibrin-associated large B cell lymphoma is a rare Epstein-Barr virus-positive lymphoma arising in restricted anatomical spaces, predominantly in immunocompetent individuals; its clinical behavior and pathophysiology remain unclear. We report two cases of fibrin-associated large B cell lymphoma that were incidentally detected in bulky uterine leiomyomas and ovarian fibromas. The first patient presented with limited-stage disease and showed an indolent clinical course, managed with surgery alone; the second presented with advanced-stage disease with malignant pleural effusion, requiring chemotherapy. Lymphoma cells in the pleural effusion shared an immunohistochemical staining profile with the primary site, and genomic analysis confirmed B cell clonality. Both patients shared an unusual Epstein-Barr virus latency pattern, possibly reflecting a locally immunosuppressed microenvironment. These cases broaden the recognized spectrum of fibrin-associated large B cell lymphoma and highlight that, although typically localized, the disease may present with concomitant involvement of multiple sites at diagnosis.

Objective Despite the recent development of various novel therapeutic approaches for relapsed/refractory diffuse large B-cell lymphoma (R/R DLBCL), optimal management of patients with R/R DLBCL who are elderly and/or unfit has not yet been established. Methods We retrospectively analyzed the efficacy and safety of the R-mEPOCH regimen comprising rituximab, etoposide, vincristine, doxorubicin, carboplatin, and prednisolone in transplant-ineligible patients with R/R DLBCL. Results In total, 22 patients were included in this study. The median patient age was 75 years old. The median number of prior lines of therapy was one (range, 1-5). The overall response rate was 68%, with 45% achieving complete response (CR) or unconfirmed CR and 23% achieving partial response. With a median follow-up of 27.8 months, the median progression-free survival and overall survival (OS) were 17.1 and 27.4 months, respectively. The 2- and 5-year OS rates were 50% and 28%, respectively. The most common grade ≥3 adverse events were neutropenia [n=18 (82%)], febrile neutropenia [n=16 (73%)], anemia [n=12 (55%)], and thrombocytopenia [n=8 (36%)]. The median total lifetime cumulative dose of anthracyclines was 281 mg/m2 (range, 69-536 mg/m2) in doxorubicin equivalents. One case of grade 1 bradycardia occurred, leading to the discontinuation of R-mEPOCH. No other cardiac adverse events of grade ≥3 and/or discontinuation of treatment were observed. Conclusion Our study suggests that the R-mEPOCH regimen may be an effective and tolerable salvage regimen for transplant-ineligible R/R DLBCL patients.

Background Primary central nervous system lymphoma is rare, and primary central nervous system T cell lymphoma is relatively uncommon, contributing to < 5% of all cases. Lymphomatosis cerebri, a rare subtype of primary central nervous system lymphoma, is characterized by extensive white-matter lesions on magnetic resonance imaging and nonspecific symptoms, such as cognitive decline and depression. Reports of lymphomatosis cerebri in adult T cell leukemia/lymphoma are limited. Case presentation A 49-year-old Japanese man gradually developed insomnia, anorexia, and weight loss over a 2-month period following work-related promotion. Initially diagnosed with depression, his condition rapidly deteriorated with cognitive decline and motor dysfunction. Despite various treatments, his symptoms persisted within a month. Upon admission, the presence of neurological abnormalities suggestive of a central nervous system disorder raised suspicion of a cerebral lesion. Diagnostic tests revealed extensive brain lesions on imaging and the presence of atypical lymphocytes (flower cells) in the cerebrospinal fluid. The patient was diagnosed with lymphomatosis cerebri due to adult T cell leukemia/lymphoma, a rare presentation in the literature. Due to irreversible brainstem damage and poor neurological prognosis, aggressive treatment was not initiated, and the patient died, with an autopsy confirming the diagnosis. Conclusion Lymphomatosis cerebri with adult T cell leukemia/lymphoma is very rare. It is crucial to promptly consider lymphomatosis cerebri as a differential diagnosis, particularly in cases of rapid cognitive decline and poor treatment response. Recognition of lymphomatosis cerebri as an important differential diagnosis for cognitive decline, and depression is necessary for timely intervention and management. Further research is required to better understand this unique and rare presentation in adult T cell leukemia/lymphoma.

We retrospectively analyzed 103 patients with untreated aggressive adult T-cell leukemia/lymphoma who received the modified EPOCH (mEPOCH) regimen, comprising etoposide, doxorubicin, vincristine, prednisolone, and carboplatin. We observed a response rate of 58% (complete response rate of 25%) and a median survival time of 9.8 months, comparable with previous studies. mEPOCH is an effective and well-tolerated alternative regimen for adult T-cell leukemia/lymphoma. Background: We retrospectively analyzed patients with untreated aggressive adult T-cell leukemia/lymphoma who received the modified EPOCH (mEPOCH) regimen. Patients and Methods: Patients received up to 6 mEPOCH cycles. Etoposide (50 mg/m(2)/day), doxorubicin (10 mg/m(2)/day), and vincristine (0.4 mg/m(2)/day) were each given as a continuous 96-hour infusion on days 1 to 4. Prednisolone (40 mg/m(2)/day) was given intravenously or orally on days 1 to 4 and then tapered and stopped on day 7, and carboplatin (dose calculated for each patient individually using Calvert's formula according to a target under the curve of 3 mg/mL/min) was given as a 2-hour intravenous infusion on day 6. Results: In 103 patients, overall response rate and complete response rate were 58% and 25%, respectively. With a median follow-up of 8.9 months, the median survival time was 9.8 months (95% confidence interval, 7.2-13.9 months). The median progression-free survival (PFS) was 4.2 months (95% confidence interval, 3.4-5.7 months). Patients who completed >= 4 cycles experienced significantly better overall survival and PFS compared with those who completed < 4 cycles. Twenty-eight patients underwent allogeneic hematopoietic stem cell transplantation after mEPOCH and demonstrated significantly prolonged overall survival and PFS compared with those who did not undergo transplantation. Conclusion: The mEPOCH regimen is effective with tolerable adverse effects and may be an alternative treatment option for adult T-cell leukemia/lymphoma. (C) 2020 Elsevier Inc. All rights reserved.

A 73-year-old man with primary myelofibrosis (PMF) was being treated with hydroxyurea, which was changed to ruxolitinib treatment because of worsening constitutional symptoms. Although ruxolitinib rapidly induced relief, he developed a high-grade fever. A comprehensive fever work-up found no apparent cause of the fever, except for PMF. Therefore, we increased the dose of ruxolitinib and added prednisolone, which was gradually withdrawn with resolution of the fever. However, the patient subsequently developed disseminated tuberculosis and died eight months after initiation of ruxolitinib. Our case highlights the importance of assessing and monitoring the immune status of patients receiving ruxolitinib.

Although gamma heavy chain disease (γ-HCD) lesions occasionally morphologically resemble angioimmunoblastic T-cell lymphoma (AITL), no association has been described in detail due to the rarity of the disease. In this report, we present a rare manifestation of methotrexate (MTX)-associated lymphoproliferative disorders (LPDs) with AITL-like features accompanied by γ-HCD in a 75-year-old man with rheumatoid arthritis (RA). A biopsy specimen was evaluated using immunohistochemistry, clonal analyses of immunoglobulin VH and T-cell receptor γ gene rearrangements by polymerase chain reaction, and Sanger sequencing for confirmation of the structure of deleted γ-HCD clones. The histological features characterized by proliferation of CD4- and PD-1-positive medium-sized T cells and arborizing high endothelial venules together with numbers of small lymphocytes, eosinophils, plasma cells, and histiocytes in the background mimicked those of AITL, but did not completely fulfill the diagnostic criteria. Clonal analysis demonstrated that the specimen contained multiple LPDs of both B-cell and T-cell lineages. Sequence analysis confirmed the co-existence of a clone responsible for production of the abnormal heavy chain. This report provides new insights into the pathology of γ-HCD. Multiple host-derived factors (e.g., RA and/or use of MTX) may be responsible for the occurrence of LPDs of multiple lineages within a single lymph node.

Myeloid sarcoma (MS) is a rare condition and is an extramedullary tumour of immature myeloid cells. It is now known that the programmed death 1 (PD‐1)/programmed death ligand 1 (PD‐L1) pathway suppresses the host antitumor responses and that these products are expressed on both tumour cells and tumour‐infiltrating cells in various malignancies. However, little is known about the significance of PD‐1/PD‐L1 expression on tumour cells and tumour microenvironmental cells in MS. To investigate the clinicopathological significance of PD‐1/PD‐L1 expression in MS, we analyzed 98 patients by immunohistochemistry. Of these, 10.2% of cases had neoplastic tumour cells positive for PD‐L1 (nPD‐L1+). However, the rate of nPD‐L1+ was <5% (range: 0.27 to 2.97%). On the other hand, PD‐L1 expression on 1 or more of stromal cells in the tumour microenvironment (miPD‐L1+) was observed in 37.8% of cases. Because all nPD‐L1+ cases expressed PD‐1 on less than 5% of tumour cells, we compared the miPD‐L1+ and miPD‐L1− groups. There was a correlation between miPD‐L1+ status and the number of PD‐1‐expressing tumour ‐infiltrating lymphocytes (PD‐1+ TILs; P = .0229). miPD‐L1+ was found to be associated with poorer overall survival and progression‐free survival (P = .00392, P = .00261, respectively). Multivariate analysis also confirmed miPD‐L1+ to be an independent poor prognostic factor. In conclusion, our study indicated that the immunotherapy blocking the PD‐1/PD‐L1 pathway may improve the clinical outcome of MS.

Polyploid chromosomes are those with more than two sets of homologous chromosomes. Polyploid chromosomal abnormalities are observed in various malignant tumors. The prognosis in such cases is generally poor. However, there are no studies examining the prognosis of diffuse large B-cell lymphoma (DLBCL) with polyploid chromosomal abnormalities. Therefore, we statistically compared the clinicopathological features between polyploid DLBCL and DLBCL without polyploid abnormalities. Herein, 51 polyploid DLBCL and 53 control (without polyploid chromosomal abnormalities) cases were examined. G-banding method was employed to define polyploidy by cytogenetic analysis. Subsequently, flow cytometric immunophenotyping and immunohistochemical staining were performed. Polyploid DLBCL was defined as DLBCL with either near-tetraploid or greater number of chromosomes, as detected by the G-band. In a survival analysis, a significantly worse overall survival (OS) was observed for polyploid DLBCL (p = 0.04; p = 0.02 in cases who received R-CHOP regimens). In a multivariate analysis of OS, polyploid chromosomal abnormalities were an independent prognostic factor. Our results suggest that polyploid chromosomal abnormalities detected through G-band may represent a new poor prognostic factor for DLBCL.

ObjectivesT-cell prolymphocytic leukemia (T-PLL) is a very rare, aggressive T-cell neoplasm. Peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS) is also a highly aggressive lymphoma. These two diseases can often be confused with each other; therefore, we aimed to determine the clinical and pathological differences between T-PLL and PTCL-NOS.MethodsWe analyzed 15 T-PLL and 91 PTCL-NOS patients and also compared clinical features between T-PLL and PTCL-NOS with leukemic presentation. Peripheral blood images and biopsy specimens were analyzed, and treatment responses were determined via imaging modalities. The clinicopathological characteristics were statistically compared.ResultsT-PLL cells were smaller in size than those of PTCL-NOS with leukemic presentation (P=.0068); moreover, PTCL-NOS cells with leukemic presentation were smaller than those of PTCL-NOS without leukemic presentation (P=.0017). Immunophenotypic patterns in T-PLL and PTCL-NOS were similar. Five-year overall survival rates of T-PLL and all PTCL-NOS patients were 57.5% and 36.8%, respectively. No significant differences were found in clinical manifestations or prognoses; T-PLL and PTCL-NOS with leukemic presentation had essentially equivalent characteristics.ConclusionT-PLL and PTCL-NOS may share common biological and clinical characteristics in Japanese patients.

Human T-cell lymphotropic virus type (HTLV)-1 Tax is a viral protein that has been reported to be important in the proliferation of adult T-cell leukemia/lymphoma (ATLL) cells and to be a target of HTLV-1-specific cytotoxic T lymphocytes (CTLs). However, it is not clear how Tax-specific CTLs behave in lymph nodes of ATLL patients. The present study analyzed the immunostaining of Tax-specific CTLs. Furthermore, ATLL tumor cells are known to be positive for forkhead box P3 (Foxp3)and to have a regulatory T (Treg)-cell-like function. The association between T-reg function and number and activity of Tax-specific CTLs was also investigated. A total of 15 ATLL lymphoma cases with human leukocyte antigen (HLA)-A24, for which Tax has a high affinity, were selected from the files of the Department of Pathology, School of Medicine, Kurume University (Kurume, Japan) using a polymerase chain reaction (PCR) method. Immunostaining was performed for cluster of differentiation (CD) 20, CD3, CD4, CD8, T-cell intracellular antigen-1 and Foxp3 in paraffin sections, and for Tax, interferon γ and HLA-A24 in frozen sections. In addition, the staining of Tax-specific CTLs (HLA-A24-restricted) was analyzed by MHC Dextramer® assay in frozen sections. In addition, the messenger RNA expression of Tax and HTLV-1 basic leucine zipper factor were also evaluated by reverse transcription-PCR. Immunohistochemical staining of Tax protein in lymphoma tissue revealed the presence of positive lymphoma cells ranging from 5 to 80%, and immunohistochemical staining of HLA-A24 revealed the presence of positive lymphoma cells ranging from 1 to 95%. The expression of Tax and HLA-A24 was downregulated by viral function. Foxp3, a marker for Treg cells, was expressed in 0-90% of cells. Several cases exhibited Tax-specific CTL (HLA-A24-restricted)-positive cells, and there was an inverse correlation between Tax-specific CTLs and Foxp3. However, neither Tax nor HLA-A24 expression was associated with CTL or Foxp3. Our study indicated the possibility that ATLL cells, which expressed Tax, target of CTL, evade the CTL-mediated immune control by expression of Foxp3 as a Treg function.

Light-chain deposition disease (LCDD) is a rare plasma cell neoplasm that secretes an abnormal immunoglobulin light chain, which is deposited in tissues, leading to organ dysfunction. Spontaneous splenic rupture is a rare and life-threatening complication of treatment with granulocyte colony-stimulating factor (G-CSF). Herein, we describe spontaneous splenic rupture after the administration of lenograstim to a patient with LCDD undergoing autologous stem cell transplantation (ASCT). The patient was successfully treated by transcatheter embolization of the splenic artery, and long-term stringent complete remission was attained. Plasma cell neoplasms, including multiple myeloma with amyloidosis, are among the most commonly reported conditions associated with spontaneous splenic rupture in patients undergoing ASCT. This finding suggests that, in addition to the effect of G-CSF on the spleen, a combination of factors, including tissue vulnerability induced by the infiltration of abnormal immunoglobulins, may be involved in the pathogenesis of spontaneous splenic rupture. Notably, splenomegaly is not always evident in these patients. Surgical treatment may not be an option, because of severe myelosuppression, and thus less invasive treatment using transcatheter embolization may be feasible.

mum assessment period of 4 weeks, however, the definition is provided in proportions and therefore each period is possible. Dosing deviations can be assessed using information from the infusion diary; however, due to the use of entire vials a 10% dosing deviation is unlikely in clinical practice. But when evaluating longer treatment periods, dose deviations can occur, usually due to extra infusions. In conclusion, this is the first study describing a formal definition of adherence to prophylaxis in haemophilia generated by a large group of professional and patient experts. Defining adherence involves different aspects with different cut-off values. Three categories were established: adherent, sub-optimally adherent and non-adherent. Acknowledgement

Programmed cell death ligand 1 (PD-L1) is expressed on both tumor and tumor-infiltrating nonmalignant cells in lymphoid malignancies. The programmed cell death 1 (PD-1)/PD-L1 pathway suppresses host antitumor responses, although little is known about the significance of PD-1/PD-L1 expression in the tumor microenvironment. To investigate the clinicopathological impact of PD-L1 expression in adult T-cell leukemia/lymphoma (ATLL), we performed PD-L1 immunostaining in 135 ATLL biopsy samples. We observed 2 main groups: 1 had clear PD-L1 expression in lymphoma cells (nPD-L1(+), 7.4% of patients), and the other showed minimal expression in lymphoma cells (nPD-L1(-), 92.6%). Within the nPD-L1(-) group, 2 subsets emerged: the first displayed abundant PD-L1 expression in nonmalignant stromal cells of the tumor microenvironment (miPD-L1(+), 58.5%) and the second group did not express PD-L1 in any cell (PD-L1(-), 34.1%). nPD-L1(+) ATLL (median survival time [MST] 7.5 months, 95% CI [0.4-22.3]) had inferior overall survival (OS) compared with nPD-L1(-) ATLL (MST 14.5 months, 95% CI [10.1-20.0]) (P = .0085). Among nPD-L1(-) ATLL, miPD-L1(+) ATLL (MST 18.6 months, 95% CI [11.0-38.5]) showed superior OS compared with PD-L1(-) ATLL (MST 10.2 months, 95% CI [8.0-14.7]) (P = .0029). The expression of nPD-L1 and miPD-L1 maintained prognostic value for OS in multivariate analysis (P = .0322 and P = .0014, respectively). This is the first report describing the clinicopathological features and outcomes of PD-L1 expression in ATLL. More detailed studies will disclose clinical and biological significance of PD-L1 expression in ATLL.

Mantle cell lymphoma (MCL) is an aggressive B cell lymphoma with a poor prognosis. It is characterized by the t(11;14)(q13;q32) translocation, resulting in over-expression of CCND1. Morphologically, MCL is categorised into two types: classical MCL (cMCL) and aggressive MCL (aMCL), with a proportion of cMCL progressing to develop into aMCL. miRNAs are currently considered to be important regulators for cell behavior and are deregulated in many malignancies. Although several genetic alterations have been implicated in the transformation of cMCL to aMCL, the involvement of miRNAs in transformation is not known. In an effort to identify the miRNAs related to the transformation of MCL, miRNA microarray analyses were used for cMCL and aMCL cases. These analyses demonstrated significant differences in the expression of seven microRNAs based on a t-test (p-value <0.05); miR-15b was greatly upregulated in aMCL. Locked nucleic acid in situ hybridization showed increased staining of miR-15b in formalin-fixed paraffin-embedded sections of aMCL. These results correlated well with the microRNA microarray analysis. Although the molecular functions of miR-15b are largely unknown, it has been found to be associated with the cell cycle and apoptosis. However, the physiological significance of increased miR-15b in MCL is still unknown. Our present findings suggest that the upregulated expression of miR-15b is likely to play an important role in the trans-formation of cMCL to aMCL.

Peliosis hepatis (PH) is a condition involving benign tumors pathologically characterized by multiple blood-filled cavities, mostly affecting the liver and spleen. Androgenic-steroids are widely used in patients with bone marrow failure syndromes (e.g.: aplastic anemia) and these patients are at increased risk of developing PH. Although patients with PH are generally asymptomatic, PH can progress to liver failure and even fatal spontaneous intraabdominal hemorrhage. Therefore, early diagnosis is critical in order to prevent life-threatening complications of PH. We herein report a patient with PH which had been treated with danazol, who presented with liver dysfunction and multiple hepatic lesions on imaging studies at the time of diagnosis. Although the patient presented with disseminated intravascular coagulation (DIC), a bone marrow biopsy revealed no evidence of leukemic transformation. The patient was diagnosed as having danazol-induced PH, and these abnormalities spontaneously resolved after the discontinuation of danazol. PH is one of the most important complications of long-term administration of androgenic-steroids. Although the mechanisms remain unclear, the multiple blood-filled cavities characteristic of PH may be responsible for the development of DIC. Therefore, monitoring of coagulation markers might also be a key strategy for early diagnosis of PH.

Double-hit (DH) lymphomas are B-cell lymphomas characterized by chromosomal rearrangements, specifically of MYC and either BCL2, BCL6 or CCND1. We reviewed 22 cases of DH lymphomas. BCL2/MYCDH lymphomas constituted the majority of these DH lymphomas (17 cases; 77%), followed by BCL6/MYC (2 cases; 9%) lymphomas. Assessing morphological features using the 2008 World Health Organization classification system, 15 cases (68%) were determined to be B-cell lymphoma, unclassifiable with features intermediate between diffuse large B-cell lymphoma (DLBCL) and Burkitt lymphoma (BCLU) (10 cases; 45%), or as DLBCL (5 cases; 23%), and 2 cases (9%) were classified as morphologically untransformed follicular lymphoma. Burkitt lymphoma was rare (1 case; 5%) among DH lymphomas. Nineteen cases were treated with R-CHOP or a high dose chemotherapy regimen. After a median follow-up of 11 months, 7 patients had died, and the 1-year survival rate was 62.5%. High dose chemotherapy did not improve the outcome. We suggest that screening of genetic variations to detect DH lymphomas is required in diagnosing all lymphomas, even those determined morphologically to be follicular lymphoma.

Abstract Introduction Programmed death ligand 1 (PD-L1) is expressed both on neoplastic cells and on tumor-infiltrating non-neoplastic cells in several types of lymphoma. The programmed death-1 (PD-1)/PD-L1 pathway inhibits antitumor immunity. However, little is known about the functions of this pathway in adult T-cell lymphoma/leukemia (ATLL). The purpose of this study was to investigate the association between clinicopathological features and PD-L1 expression in ATLL. Methods We reviewed 134 biopsy samples diagnosed as ATLL including 61 cases in the international peripheral T-cell lymphoma study and 73 cases submitted to the Department of Pathology at Kurume University for consultations. PD-L1 immunohistochemical staining (IHC) was performed on formalin fixed paraffin embedded samples. According to staining patterns of PD-L1 IHC, we categorized cases of ATLL into several groups. First, cases with ATLL cells with distinct and circumferential membranous and/or cytoplasmic staining of PD-L1 were defined as neoplastic PD-L1 positive ATLL (nPD-L1(+) ATLL) whereas cases without such staining pattern of PD-L1 in ATLL cells were classified as neoplastic PD-L1 negative ATLL (nPD-L1(-) ATLL). Second, among nPD-L1(-) ATLL group, cases with non-ATLL cells with PD-L1 positivity were defined as microenvironmental PD-L1 positive ATLL (miPD-L1(+) ATLL) whereas cases without PD-L1 positive non-ATLL cells were difined as PD-L1 negative ATLL (PD-L1(-) ATLL). Clinical features analyzed in this study were age at the diagnosis, sex, Shimoyama classification, Eastern Cooperative Oncology Group performance status, LDH, presence or absence of hypercalcemia, Ann Arbor stage, Japan Clinical Oncology Group prognostic index, and complete response (CR) or CR uncertain as therapeutic effect. Morphological variant, and immunohistochemical expression in neoplastic cells of PD-1, CD30, CCR4, and FoxP3 were included in pathological features. The numbers of PD-1 positive tumor-infiltrating lymphocytes (TILs) were counted in each sample as quantitative analysis. Clinicopathological features of the patients were statistically compared using chi-square tests or Fisher's exact tests. Wilcoxon rank sum tests were performed to compare the number of PD-1 positive TIL counts between different groups. The Kaplan-Meier method was used to estimate the overall survival (OS). To compare the survival curves, we performed the log-rank test. Univariate and multivariate analyses were used to evaluate the influence of prognostic factors on the OS by the Cox proportional hazards models. Results The percentage of nPD-L1(+) ATLL and nPD-L1(-) ATLL were 7.5% (10/134) and 92.5% (124/134), respectively. Among nPD-L1(-) ATLL, miPD-L1(+) ATLL were 58.2% (78/134) whereas PD-L1(-) ATLL were 34.3% (46/134). Statistical comparison of clinicopathological features between nPD-L1(+) ATLL and nPD-L1(-) ATLL showed significant difference in overall survival (OS) although significant difference was not observed in other clinicopathological features. NPD-L1(+) ATLL had inferior overall survival (OS) compared with nPD-L1(-) ATLL (p = 0.0098) (Figure1). The PD-L1 expression in neoplastic cells maintained prognostic value for OS in univariate analysis (p = 0.026) and multivariate analysis (p = 0.034). Statistical comparison of clinicopathological features between miPD-L1(+) ATLL and PD-L1(-) ATLL showed statistically significant differences in the positive rate of hypercalcemia (10%, 8/78 in miPD-L1(+) ATLL vs 24%, 11/46 in PD-L1(-) ATLL, p = 0.045), the positive rate of skin lesion (23%, 18/77 in miPD-L1(+) ATLL vs 7%, 3/46 in PD-L1(-) ATLL, p = 0.02), and the number of PD-1 positive TILs (3.60/hpf in average in miPD-L1(+) ATLL vs 0.28/hpf in PD-L1(-), p = 0.0007). MiPD-L1(+) ATLL had superior overall survival (OS) compared with PD-L1(-) ATLL (p = 0.0043) (Figure 2). The expression of PD-L1 in non-ATLL cells maintained prognostic value for OS in univariate analysis (p = 0.0056) and multivariate analysis (p = 0.002). Conclusion This study, for the first time, described the impact of PD-L1 expression on clinicopathological features of ATLL. More effective immunotherapy for the PD-1/PD-L1 pathway may be selected according to PD-L1 expression in ATLL. Disclosures No relevant conflicts of interest to declare.