Optimization of immune checkpoint inhibitor treatment planning for relapsed or refractory extranodal NK/T cell lymphoma.

Pembrolizumab (anti-programmed cell death-ligand 1 inhibitor) is a promising salvage therapeutic option for relapsed/refractory extranodal NK/T-cell lymphoma (R/R ENKTL). However, the appropriate duration of pembrolizumab use in R/R ENKTL patients and the optimal timing for administering pembrolizumab remain undetermined. We collected and analyzed clinical information on R/R ENKTL 58 patients who received pembrolizumab to evaluate the optimal treatment durations and clinical information for considering treatment interruption. Treatment outcomes were assessed by 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) and Epstein Barr virus DNA (EBV DNA) every 3 months. Nineteen (32.8%) patients had been treated with more than three chemotherapies before pembrolizumab administration. The best response rate towards the first try of pembrolizumab was 38.9% (31.5% complete response rate (CR), 7.4% partial response (PR)). During the 41.8-month median follow-up duration, the median progression-free survival (PFS) was 3.1 months, and the median overall survival (OS) was 7.1 months. The failure group, which was characterized by Deaville score (DS) 3-4 and circulating EBV detection, or DS 5 with/without EBV detection, had the worst PFS (p < 0.001) and OS (p < 0.001), followed by the high (DS 1-2 and EBV detection, or DS 3-4 and EBV not detected) and low-risk groups (DS 1-2 and EBV not detected). Among the 21 patients who achieved the best response at the first pembolizumab try, the patients who received planned 24 cycles presented better PFS than those who received incomplete cycles (57.6 months vs 20.9 months, P-value = 0.012). Among 13 patients who received avelumab or pembrolizumab in advance, a few who responded to the second trial of pembrolizumab administration had over one year of chemotherapy vacation. Determining the discontinuation or continuation of pembrolizumab would be considered in selected cases assessed by PET-CT and EBV monitoring. Disruption of pembrolizumab treatment may be advisable for the low-risk group(DS 1-2 and EBV not detected), whereas continuation could be warranted for the high-risk group (DS 1-2 and EBV detection, or DS 3-4 and EBV not detected). Moreover, it might be critical to maintain over 24 cycles to improve the survival outcome of R/R ENKTL.

Primary nodal Epstein-Barr virus-positive T-cell/NK-cell lymphoma: Real-world experience.

PTCL-EBV is a disease entity newly recognized in the WHO-HAEMS5 and the ICC of Mature Lymphoid neoplasms classification. Previously, it was classified as a subtype within PTCL-NOS and was known to have a poor prognosis. However, the clinical feature and treatment outcomes are not well known. This retrospective observational study was conducted on patients diagnosed with PTCL-EBV at Samsung Medical Center through a pathology review from 2000 to 2020. We analyzed clinical data from 14 patients. We conducted an investigation of patients with PTCL-EBV into immunohistochemistry and analysis of survival outcomes for each treatment regimen. We analyzed both overall survival and progression-free survival for each treatment regimen. 25% were beta-F1 positive, and 67% were TCRγ positive. TIA-1 and granzyme B exhibited positive results in all cases, whereas the NK cell marker CD56 was negative in only 11% of patients. The CD3 was observed in all of patients. And, the CD4 was 43% positive. The CD8 were investigated in 8 patients, with 37.5% positive. Hepatosplenomegaly was observed in 55% of patients, and 70% of patients displayed B symptoms at the time of diagnosis. Patients who received CHOP or CVP treatment had a median PFS of 2.2 months (95% CI 1.9-2.5 months), and patients who received other treatments had a median PFS of 5.1 months (NA). The objective response rate (ORR) for ICE/dexa as the first or second line treatment was 100% (3 out of 3). But, ORR of CHOP or CVP as the first line treatment was 33.3% (3 out of 9). The median overall survival (OS) for the group that received HSCT after achieving a response was 34.6 months (95% CI 0-74.6 months), and the median OS for the group that did not receive HSCT was 5.0 months (95% CI 2.1-7.9 months) (p=0.04). In conclusion, in the context of PTCL-EBV, despite a limited sample size, the ICE/Dexa regimen shows potential benefits in terms of ORR and PFS. Furthermore, the application of HSCT following the attainment of a complete response may prove advantageous.

Histological criteria for selecting patients who need clonality test for non-gastric MALT lymphoma diagnosis.

The histological diagnosis of extranodal marginal zone lymphoma of the mucosa-associated lymphoid tissue (MALT lymphoma) is difficult for pathologists. Recently, digital pathology systems have been widely used to provide tools that can objectively measure lesions on slides. In this study, we measured the extent of marginal zone expansion in suspected MALT lymphoma cases and compared the results with those of a molecular clonality test. In total, 115 patients who underwent an IGH gene rearrangement test for suspected MALT lymphoma were included in this study. All cases were histologically classified into three patterns; "small lymphoid aggregates with no germinal center (Pattern 1)," "lymphoid follicles with germinal center (Pattern 2)" and " fused marginal zone or diffuse small lymphocytic proliferation (Pattern 3)." The proportions of monoclonality in Pattern 1, 2, and 3 were 25.0%, 55.0%, and 97.9%, respectively. The ratios of marginal zone thickness to germinal center diameter and entire lymphoid follicle area to germinal center area were measured in Pattern 2 cases using a digital pathology system. Combining the width cutoff of 1.5 and the areal cutoff of 3.5, the sensitivity, specificity, positive predictive value, and negative predictive value for MALT lymphoma were 96.97%, 70.37%, 80.00%, and 95.00%, respectively. In conclusion, through objective measurement of the marginal zone, suspected cases of MALT lymphoma requiring a molecular clonality test can be effectively selected.

Feasibility of Circulating Tumor DNA Analysis in Patients with Follicular Lymphoma.

PURPOSE: The feasibility of sequencing circulating tumor DNA (ctDNA) in plasma as a biomarker to predict early relapse or poor prognosis in patients with follicular lymphoma (FL) receiving systemic immunochemotherapy is not clear. MATERIALS AND METHODS: We sequenced DNA from cell-free plasma that was serially obtained from newly diagnosed FL patients undergoing systemic immunochemotherapy. The mutation profiles of ctDNA at the time of diagnosis and at response evaluation and relapse and/or progression were compared with clinical course and treatment outcomes. RESULTS: Forty samples from patients receiving rituximab-containing immunochemotherapy were analyzed. Baseline sequencing detected mutations in all cases, with the major detected mutations being KMT2C (50%), CREBBP (45%), and KMT2D (45%). The concentration of ctDNA and tumor mutation burden showed a significant association with survival outcome. In particular, the presence of mutations in CREBBP and TP53 showed poor prognosis compared with patients without them. Longitudinal analysis of ctDNA using serially collected plasma samples showed an association between persistence or reappearance of ctDNA mutations and disease relapse or progression. CONCLUSION: Analysis of ctDNA mutations in plasma at diagnosis might help predict outcome of disease, while analysis during follow-up may help to monitor disease status of patients with advanced FL. However, the feasibility of ctDNA measurement must be improved in order for it to become an appropriate and clinically relevant test in FL patients.

Tumor-infiltrating T lymphocytes evaluated using digital image analysis predict the prognosis of patients with diffuse large B-cell lymphoma.

BACKGROUND: The implication of the presence of tumor-infiltrating T lymphocytes (TIL-T) in diffuse large B-cell lymphoma (DLBCL) is yet to be elucidated. We aimed to investigate the effect of TIL-T levels on the prognosis of patients with DLBCL. METHODS: Ninety-six patients with DLBCL were enrolled in the study. The TIL-T ratio was measured using QuPath, a digital pathology software package. The TIL-T ratio was investigated in three foci (highest, intermediate, and lowest) for each case, resulting in TIL-T-Max, TIL-T-Intermediate, and TIL-T-Min. The relationship between the TIL-T ratios and prognosis was investigated. RESULTS: When 19% was used as the cutoff value for TIL-T-Max, 72 (75.0%) and 24 (25.0%) patients had high and low TIL-T-Max, respectively. A high TIL-T-Max was significantly associated with lower serum lactate dehydrogenase levels (p < .001), with patient group who achieved complete remission after RCHOP therapy (p < .001), and a low-risk revised International Prognostic Index score (p < .001). Univariate analysis showed that patients with a low TIL-T-Max had a significantly worse prognosis in overall survival compared to those with a high TIL-T-Max (p < .001); this difference remained significant in a multivariate analysis with Cox proportional hazards (hazard ratio, 7.55; 95% confidence interval, 2.54 to 22.42; p < .001). CONCLUSIONS: Patients with DLBCL with a high TIL-T-Max showed significantly better prognosis than those with a low TIL-T-Max, and the TIL-T-Max was an independent indicator of overall survival. These results suggest that evaluating TIL-T ratios using a digital pathology system is useful in predicting the prognosis of patients with DLBCL.

Infiltrative fibrous lesion of the facial nerve mimicking a facial nerve tumor.

PURPOSE: To report three cases of facial nerve lesions that were clinically expected to be facial nerve tumors but showed fibrotic infiltration without any apparent signs of a specific tumor on histopathological findings. We also aimed to investigate the clinical characteristics of these cases. METHODS: Medical records of patients who underwent surgery for facial nerve lesions were reviewed. RESULTS: All three cases initially had House-Brackmann (HB) grade IV-V facial nerve palsy. On radiological imaging, schwannoma or glomus tumor originating from the facial nerve was suspected. All patients underwent complete surgical removal of the neoplasm followed by facial nerve reconstruction using the sural nerve. The lesions were histologically confirmed as infiltrative fibrous lesions without tumor cells. In two cases, facial nerve palsy improved to HB grade III by nine months post-surgery, and there were no signs of recurrence on follow-up MRI. The other case, after 1 year of follow-up, showed persistence of HB grade V facial nerve palsy without any evidence of recurrence. CONCLUSION: Fibrotic lesions of the facial nerve could mimic primary facial nerve tumors. Clinicians should consider this condition even when a facial nerve tumor is suspected.

Topography and probability diagram of cervical and intra-parotid lymph node metastasis in parotid gland cancer.

In parotid gland cancer (PGC), cervical lymph node metastasis (LNM) and intra-parotid LNM are known as significant indicators of poor prognosis. However, the topography of LNM in the affected parotid gland and the lymphatic progression of PGC has never been explored in detail. This was a retrospective analysis of data from 423 patients with previously untreated primary PGC (2005 to 2020), excluding patients with squamous cell carcinoma, lymphoma or metastatic disease in the parotid gland. The pattern of LNM was analyzed by neck sub-level and parotid sub-site. Using the conditional probability of neck level involvement, a probability diagram was plotted on several thresholds to visualize the sequential progression of LNM in PGC. The pattern of LNM progression was found to be similar between low- and high-grade pathology, but the incidence differed significantly (8.0% vs. 45.4%). Intra-parotid LNs and level IIa LNs were the most common sites (57.3% and 61.0%) of LNM in PGC, followed by level III (31.7%), Ib (25.6%), IV (22.0%), IIb (20.7%) and Va (20.7%) LNM. In intra-parotid LNs, the incidence of LNM in the deep parotid LNs was relatively low (9.4%); most intra-parotid LNMs were observed in the superficial parotid (90.6%) and peri-tumoral (in contact with the tumor) (31.3%) LNs. LNM to levels Ia, Vb and contra-lateral LNM occurred only in the very late stage. Our results provide detailed information about LNM progression in PGC at the sub-level and can help clinicians decide the treatment extent, including surgery or radiation.

Impact of dysplasia at resection margin on oncologic outcome after curative resection of oral tongue squamous cell carcinoma: significance of high-grade dysplastic resection margin.

BACKGROUND: This study aimed to compare the oncologic outcomes among negative, close, positive, and dysplasia resection margins (RMs) with oral tongue squamous cell carcinoma (OSCC) and to investigate the impact of dysplastic RMs. METHODS: The 565 patients were retrospectively analyzed and divided into four groups according to RM. Dysplasia was classified into mild, moderate, and severe subgroups. RESULTS: RMs consisted of negative (62.1%), close (27.1%), positive (2.1%), and dysplastic (8.7%). In multivariate analysis, advanced T/N stages and positive RM were significant risk factors for overall survival, while dysplasia at the RM was not a significant risk factor for locoregional recurrence or overall survival. In subgroup analysis of patients with dysplastic margin, RM with severe dysplasia showed higher recurrence than mild and moderate dysplasia. CONCLUSIONS: Dysplastic RM was not a risk factor for recurrence and survival. Severe dysplasia RM should be carefully observed due to higher recurrence compared to other dysplasia RMs.

A retrospective analysis of ibrutinib outcomes in relapsed or refractory mantle cell lymphoma.

Background: While treatment strategies for mantle cell lymphoma (MCL) have evolved, patients often experience disease progression and require additional treatment therapies. Ibrutinib presents a promising option for relapsed or refractory MCL (RR-MCL). This study investigated real-world treatment outcomes of ibrutinib in patients with RR-MCL. Methods: A single-center retrospective analysis investigated clinical characteristics and survival outcomes of patients with RR-MCL, treated with ibrutinib. Results: Forty-two patients were included, with 16 received rituximab and bendamustine, and 26 receiving anthracycline-based regimens as front-line treatment. During a median follow-up of 46.0 months, the response rate to ibrutinib was 69%, with 12 CRs and 8 partial responses. Disease progression (54.8%) and adverse events (11.9%) were the primary reasons for discontinuation. Median progression-free survival (PFS) and overall survival (OS) were approximately 16.4 and 50.1 months, respectively. Patients older than 70 years (P=0.044 and P=0.006), those with splenomegaly (P=0.022 and P=0.006), and those with a high-risk simplified Mantle Cell Lymphoma International Prognostic Index (sMIPI) (P＜0.001 and P＜0.001) exhibited siginificantly inferior PFS and OS. Notably, patients with a high-risk sMIPI relapsed earlier. Post-ibrutinib treatment yilded an OS of 12.2 months, while clinical trial participants demonstrated superior survival compared to those receiving chemotherapy alone. Conclusion: This study underscores the importance of considering patient characteristics before administering ibrutinib as salvage therapy. Early relapse was associated with poor outcomes, highlighting the need for novel therapeutic strategies.

The impact of sMICA/sMICB on immunochemotherapy outcomes in newly diagnosed diffuse large B-cell lymphoma.

Introduction: Soluble MHC class I-related chain A (sMICA) and B (sMICB) play a critical role tumor evolution and poor prognosis through an immune evasion mechanism. Thus, this study determines the interaction between sMICA/sMICB and the tumor immune environment in newly diagnosed diffuse large B-cell lymphoma (ND-DLBCL). Methods: We analyzed sMICA/sMICB, cytokine in serum, and macrophage polarization analysis in tissue samples before the first chemotherapy administration. This research was performed to investigate the correlation between sMICA/sMICB expression and treatment outcomes as well as their influence on the immune system within ND-DLBCL. Results: Of the 262 patients, 47.3% (n = 124) presented stage III or IV at diagnosis and 50.8% (n = 133) had a high International Prognostic Index (IPI ≥ 3). The patients with high (p = 0.034 and 0.004), elevated lactate dehydrogenase (p = 0.002 and 0.030), advanced stage (p = 0.003 and 0.012), and higher IPI risk (p = 0.009, and 0.032) correlated with the detection of sMICA or sMICB. The median progression-free survival (PFS) of patients with sMICA (p = 0.006) or sMICB (p =0.032) was inferior. Among the patients with advanced-stage or high IPI, those with sMICA or sMICB presented an inferior PFS and OS compared to those without. TNF-a, a pro-inflammatory cytokine, showed statistical significance with detected sMICA (p = 0.035) or sMICB (p = 0.044). Among anti-inflammatory cytokines, IL-1RA (P-value = 0.013) and IL-10 (p = 0.005) were associated with detecting sMICB, but not sMICA. In tissue samples, sMICA or sMICB detection did not correlate with the CD68/CD163 ratio. Discussion: Conclusively, the identification of sMICA/sMICB presented unfavorable immunochemotherapy outcomes, and it was assumed that sMICA or sMICB and various cytokines interact, but the relationship with macrophage differentiation is unclear. Therefore, further research is needed to determine the relationship between sMICA/sMICB and tumor microenvironment in DLBCL.

Differences in mutational signature of diffuse large B-cell lymphomas according to the primary organ.

BACKGROUND: Comprehensive molecular subtyping of diffuse large B-cell lymphoma (DLBCL) through genetic profiling has broadened our understanding of DLBCL biology. In this study, we investigated whether DLBCL, not otherwise specified (NOS) shows differences in mutational patterns depending on the primary organ. PATIENTS AND METHODS: Panel-based next-generation sequencing was performed on 345 DLBCL from various primary organs, and patterns of mutations according to primary organs were analyzed. RESULTS: DLBCL showed a characteristic mutational signature in several primary organs. Among them, the mutational pattern of DLBCL in the breast and ileocecal area was particularly different from that of other DLBCL NOS. In breast DLBCL, MYD88L265P (57.1%), CD79B mutation (42.9%), and CDKN2A/B loss (71.4%) were found at high frequencies, which were similar to the mutation patterns of DLBCL of immune-privileged sites compared with DLBCL NOS. DLBCL in the ileocecal area showed a characteristic mutation pattern with the most frequent TP53 mutation (52.6%) and 18q21 gain (42.1%). This was also different from the mutational pattern observed in the stomach or other intestines. In discriminant analysis, DLBCL of the breast and ileocecal area tended to form separate genetic constellations from other DLBCL NOS. CONCLUSION: DLBCL NOS has a characteristic mutational profile that depends on the primary organ. In particular, the mutational signature of DLBCL in the breast and ileocecal area was heterogeneous compared with that of other DLBCL NOS. Further research is needed to determine whether primary DLBCL in the breast and ileocecal area can be classified as an independent subtype.

A unique expression pattern of LAG3 distinct from that of other immune checkpoints in diffuse large B-cell lymphoma.

BACKGROUND: Although some patients with diffuse large B-cell lymphoma (DLBCL) show a response to immunotherapy, there are still many who do not respond. This suggests that various immune checkpoints are complicatedly intertwined in the composition of the tumor microenvironment of DLBCL. PATIENTS AND METHODS: To comprehensively understand the expression of various immune checkpoint genes in DLBCL, we performed NanoString assay in 98 patients to investigate 579 genes. In addition, we performed immunohistochemistry for LAG-3 and PD-L1 to compare the results with expression in NanoString assay. RESULTS: As a result of hierarchical clustering of NanoString assay, 98 DLBCLs were classified into three tumor immune microenvironment clusters. Most immune checkpoint genes showed the highest expression in cluster A and the lowest in cluster C. However, the expression of LAG3 was the highest in cluster C and the lowest in cluster A, showing an expression pattern opposite to that of other immune checkpoint genes. In Cluster A, the expression of genes related to T-cell activity such as CD8A and GZMB was increased. In Cluster C, the expression of genes related to major histocompatibility complex molecules was the highest. Immunohistochemical stains showed modest agreement with the NanoString results but did not help clustering. CONCLUSION: Our results show that the unique expression pattern of LAG3 in DLBCL contrasts with that of other immune checkpoints. We suggest that the combination of anti-PD-1/PD-L1 and anti-LAG-3 blockades in the immunotherapy of DLBCL patients can have a synergistic effect, improving the immunotherapy efficacy and outcome in DLBCL patients.

Real-World Data Analysis of Survival Outcomes and Central Nervous System Relapses in Testicular Diffuse Large B Cell Lymphoma.

Background: Primary testicular lymphoma is a rare type of non-Hodgkin lymphoma, mostly of the diffuse large B cell lymphoma (DLBCL). Although a consensus on standard treatment has been established, unresolved issues remain, such as recurrence in the central nervous system (CNS). Methods: We retrospectively analyzed the clinical characteristics and survival outcomes of 65 testicular DLBCL patients according to clinical settings and treatment modalities. Results: The median age of the patients in our study was 65 years, and two-thirds of them had disease limited to one testis. There was no right or left lateralization of testicular involvement. Over a median follow-up of 53.9 months (95% confidence interval 34.0-73.7 months), patients with stage I disease and a low international prognostic index score showed better survival outcomes than those in other categories. Orchiectomy, six cycles of chemotherapy, and radiation therapy (RT) to the contralateral testis demonstrated survival benefits, whereas CNS prophylaxis therapy did not reduce CNS recurrence. During the follow-up period, the survival curves showed continuous decline, mostly due to disease progression. CNS recurrence was observed in 15% of patients, and parenchymal involvement was dominant. However, no factors were associated with CNS recurrence in our analyses. Although our molecular analyses were performed in a small number of patients, MYD88, CD79B, and PIM1 mutations were frequent. Conclusion: In our study, treatment with orchiectomy, six cycles of immunochemotherapy, and contralateral RT was effective. However, because CNS prophylaxis is an essential part of testicular DLBCL management, better treatment strategies than intrathecal therapy are required.

Retrospective analysis of diagnosis and therapeutic strategies for patients with hepatosplenic T cell lymphoma.

Hepatosplenic T cell lymphoma (HSTCL) is a rare and aggressive lymphoma with no standard treatment and poor treatment response. From 2001-2021, 20 from a lymphoma cohort of 7247 patients (0.27%) were diagnosed with HSTCL at Samsung Medical Center. The median age at the time of diagnosis was 37.5 (range, 17-72) years, and 75.0% of patients were male. Most patients had B symptoms, hepatomegaly, and splenomegaly. Lymphadenopathy was found in only 31.6% of patients, and increased PET-CT uptake was found in 21.1% of patients. Thirteen patients (68.4%) expressed T cell receptor (TCR) γδ, and 6 patients (31.6%) expressed TCRαß. The median progression-free survival (PFS) for the entire cohort was 7.2 months (95% CI, 2.9-12.8), and the median overall survival (OS) was 25.7 months (95% CI, not calculated). In subgroup analysis, the overall response rate (ORR) was 100.0% in the ICE/Dexa group and 53.8% in the anthracycline-based group, and the complete response rate was 83.3% in the ICE/Dexa group and 38.5% in the anthracycline-based group. The ORR was 50.0% in the TCRαß group and 83.3% in the TCRγδ group. The OS was not reached in the autologous hematopoietic stem cell transplantation (HSCT) group and was 16.0 months (95% CI, 15.1-16.9) in the non-transplant group at the data cutoff time (P value 0.015). In conclusion, HSTCL is rare but has a very poor prognosis. The optimal treatment strategy is not defined. More genetic and biological information is needed.

Clinicopathological and molecular genetic characteristics of primary gastric follicular lymphoma.

Primary gastric follicular lymphomas (FLs) have been rarely reported, and little is known about their characteristics. In the present study, we report 5 cases of primary gastric FL and describe their clinicopathological and molecular genetic features. A total of 7 samples from 5 patients were investigated for clinicopathological characteristics and somatic mutations by the targeted sequencing of 50 lymphoma-related genes. Two cases were identified as slightly elevated submucosal tumors and 3 cases as polypoid tumors. Histologically, all cases were low-grade FLs. The immunoprofile was CD20+/CD10+/BCL2+ in 4 cases and CD20+/CD10+/BCL2- in 1 case. The immunostaining pattern for CD21 was similar to that of classic FL. BCL2 rearrangement was not identified in fluorescence in situ hybridization studies in any of the 5 cases. Next-generation sequencing analysis showed mutations in genes involved in epigenetic modifications (KMT2D, ARID1A, EP300, and CREBBP), NK-kB pathway (CARD11), and JAK-STAT pathway as found in classic FL. All cases presented with clinical I without the involvement of regional or systemic lymph nodes. Four patients were well, whereas 1 patient who received endoscopic mucosal resection of tumor without additional chemotherapy or radiotherapy experienced 3 relapses. In conclusion, primary gastric FL is characterized by a low-grade neoplasm with infrequent BCL2 rearrangement. After resection of the lesion, additional treatment such as radiation therapy or chemotherapy is required as there is a possibility of recurrence.

TET2 and LILRB1 mutations are frequent in Epstein-Barr virus-positive diffuse large B-cell lymphoma especially in elderly patients.

BACKGROUND: Diffuse large B-cell lymphoma (DLBCL) harboring Epstein-Barr virus (EBV) primarily occurs in patients who have underlying immunodeficiency or in elderly patients but is also reported in young, immunocompetent patients. The authors investigated the pathologic differences in EBV-positive DLBCL in these three groups of patients. METHODS: In total, 57 patients with EBV-positive DLBCL were included in the study; of these, 16 patients had associated immunodeficiency, 10 were young (younger than 50 years), and 31 were elderly (aged 50 years or older). Immunostaining for CD8, CD68, PD-L1, and EBV nuclear antigen 2, and panel-based next-generation sequencing was performed on formalin-fixed, paraffin-embedded blocks. RESULTS: Immunohistochemistry revealed EBV nuclear antigen 2 positivity in 21 of the 49 patients. The degree of CD8-positive and CD68-positive immune cell infiltration and PD-L1 expression did not differ significantly in each group. Extranodal site involvement was more common in young patients (p = .021). In mutational analysis, the genes with the highest mutation frequency were PCLO (n = 14), TET2 (n = 10), and LILRB1 (n = 10). For the TET2 gene, all 10 mutations were found in elderly patients (p = .007). Compared with a validation cohort, both TET2 and LILRB1 showed a higher mutation frequency in EBV-positive patients than in EBV-negative patients. CONCLUSIONS: EBV-positive DLBCL occurring in three different age and immune status groups showed similar pathologic characteristics. Notably, a high frequency of TET2 and LILRB1 mutations was characteristic of this disease in elderly patients. Further studies are needed to determine the role of TET2 and LILRB1 mutations in the development of EBV-positive DLBCL along with immune senescence. PLAIN LANGUAGE SUMMARY: Epstein-Barr virus-positive diffuse large B-cell lymphoma occurring in three different groups (immunodeficiency-associated, young, and elderly) showed similar pathologic characteristics. The frequency of TET2 and LILRB1 mutations was high in elderly patients with Epstein-Barr virus-positive diffuse large B-cell lymphoma.

Case Report of Erdheim-Chester Disease Successfully Treated with Pegylated Interferon: A Single-Center Experience.

Erdheim-Chester disease (ECD), also known as non-Langerhans cell histiocytosis, is a multi-systemic disease with unclear pathogenesis. Based on a small number of case studies, pegylated interferon-α (PEG-IFN-α) has been used as the front-line treatment option. However, there are limited data regarding administration of ropegylated-interferon α-2b (ROPEG-IFN-α 2b) for ECD patients. Herein, we report two cases of severe ECD treated with two types of PEG-IFN-α. One patient with heart and skeleton involvement and BRAF V600E mutation was treated with weekly PEG-IFN-α 2a. Another patient with bone involvement and no BRAF V600E mutation was administered monthly ROPEG-IFN-α 2b. The two types of PEG-IFN-α showed excellent disease control, excellent survival outcomes, and manageable toxicities in ECD patients. These results suggest that ROPEG-IFN-α 2b could be used equivalently to PEG-IFN-α 2a for management of advanced ECD.

Comparison of histological and molecular features of pediatric-type follicular lymphoma and pediatric nodal marginal zone lymphoma.

Pediatric-type follicular lymphoma and pediatric nodal marginal zone lymphoma are pediatric B cell lymphomas with similar clinical characteristics but distinct histological features. We investigated the differences between pediatric-type follicular lymphoma and pediatric nodal marginal zone lymphoma by comparing their histological and molecular characteristics. A total of 5 pediatric-type follicular lymphoma and 11 pediatric nodal marginal zone lymphoma patients were included in the study. In the histological review, 5 of the 16 cases showed overlapping morphological features of pediatric-type follicular lymphoma and pediatric nodal marginal zone lymphoma; hence, they were reclassified as "mixed type." In molecular analysis, using panel-based massively parallel sequencing, MAP2K1, TNFRSF14, and IRF8 mutations were found in 6, 3, and 2 of the 11 pediatric nodal marginal zone lymphoma patients, respectively, and IRF8 mutation was found in one of the five pediatric-type follicular lymphoma patients. There were no significant differences in genetic alterations established from the histologically reclassified diagnosis as well as the initial diagnosis. Pediatric-type follicular lymphoma and pediatric nodal marginal zone lymphoma showed morphological overlap in some cases, and no difference between the two was found upon molecular analysis. These findings suggest the possibility that pediatric-type follicular lymphoma and pediatric nodal marginal zone lymphoma are single entity pediatric B-cell lymphoma with broad morphological spectrum.

Circulating Tumor DNA-Based Genotyping and Monitoring for Predicting Disease Relapses of Patients with Peripheral T-Cell Lymphomas.

PURPOSE: Plasma circulating tumor DNA (ctDNA) could reflect the genetic alterations present in tumor tissues. However, there is little information about the clinical relevance of cell-free DNA genotyping in peripheral T-cell lymphoma (PTCL). MATERIALS AND METHODS: After targeted sequencing plasma cell-free DNA of patients with various subtypes of PTCL (n=94), we analyzed the mutation profiles of plasma ctDNA samples and their predictive value of dynamic ctDNA monitoring for treatment outcomes. RESULTS: Plasma ctDNA mutations were detected in 53 patients (56%, 53/94), and the detection rate of somatic mutations was highest in angioimmunoblastic T-cell lymphoma (24/31, 77%) and PTCL, not otherwise specified (18/29, 62.1%). Somatic mutations were detected in 51 of 66 genes that were sequenced, including the following top 10 ranked genes: RHOA, CREBBP, KMT2D, TP53, IDH2, ALK, MEF2B, SOCS1, CARD11, and KRAS. In the longitudinal assessment of ctDNA mutation, the difference in ctDNA mutation volume after treatment showed a significant correlation with disease relapse or progression. Thus, a ≥ 1.5-log decrease in genome equivalent (GE) between baseline and the end of treatment showed a significant association with better survival outcomes than a < 1.5-log decrease in GE. CONCLUSION: Our results suggest the clinical relevance of plasma ctDNA analysis in patients with PTCL. However, our findings should be validated by a subsequent study with a larger study population and using a broader gene panel.