Lymph nodes are secondary lymphoid organs localized throughout the body that typically appear as bean-like nodules. Numerous antigen-presenting cells, including dendritic cells and macrophages, that mediate host defense responses against pathogens, such as bacteria and viruses, reside within lymph nodes. To react to cancer cell-derived antigens in a variety of cancers, antigen-presenting cells induce cytotoxic T lymphocytes (CTLs). In relation to anticancer immune responses, macrophages in the lymph node sinus have been of particular interest because a number of studies involving both human specimens and animal models have reported that lymph node macrophages expressing CD169 play a key role in activating anticancer CTLs. Recent studies have indicated that dysfunction of lymph node macrophages potentially contributes to immune suppression in elderly patients and immunological “cold” tumors. Therefore, in anticancer therapy, the regulation of lymph node macrophages is a potentially promising approach.

There are numerous macrophages and dendritic cells in lymph nodes (LNs). Recent studies have highlighted that sinus macrophages (SMs) in LNs possess antigen-presenting capabilities and are related to anti-cancer immune responses. In this study, we assessed the distribution of SMs in mesenteric LNs removed during surgery for colorectal cancer. A marked reduction of SMs was noted in elderly patients, particularly those over 80 years old. We observed a disappearance of CD169-positive cells in LNs where SMs were reduced. In silico analysis of publicly available single-cell RNA sequencing data from LNs revealed that CD169-positive macrophages express numerous genes associated with antigen presentation and lymphocyte proliferation, similar to dendritic cells’ functions. In conclusion, our study demonstrates that SMs, potentially crucial for immune activation, diminish in the LNs of elderly patients. This reduction of SMs may contribute to the immune dysfunction observed in the elderly.

To elucidate long-term outcome in primary conjunctival lymphoma, a review was conducted of 31 consecutive patients: 21 men and 10 women with an age range of 28 to 85 (median, 61) years at presentation and follow-up periods ranging from 1 to 19 (median, 7) years. Conjunctival lymphoma was on the right side in 10 patients, on the left side in 12, and on both sides in 9. Upper, lower, or both fornix lesions in 28 patients were all diagnosed as extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma), while thick nasal bulbar conjunctival lesions in 3 patients were differently diagnosed as MALT lymphoma, diffuse large B-cell lymphoma, and follicular lymphoma, respectively. Seven patients underwent local radiation (30 Gy): as initial treatment in 5 patients and treatment for relapse in 2 patients. The remaining 24 patients were observed without additional treatment after excisional biopsy: 5 of these 24 patients showed relapse 0.5 to 6 years later and underwent excisional biopsy again that revealed MALT lymphoma. Of the 5 patients with relapse, only one with second-time relapse underwent radiation. Fluorodeoxyglucose positron emission tomography was performed in 18 patients and showed no systemic lesions: high uptake was noted in the residual conjunctival lesions of 4 patients and in the relapsed conjunctival lesions of 3 patients. One patient died of rectal cancer while no patients died of lymphoma. Observation is an option in patients with primary conjunctival lymphoma after excisional biopsy. Radiation is a treatment option in the case of relapse.

Atypical lymphoplasmacytic and immunoblastic proliferation (ALPIBP) was first reported in 1984 as characteristic histological findings in lymph nodes associated with autoimmune diseases, but it has not been clearly defined to date. To summarize the histological characteristics and clinical diagnoses associated with ALPIBP, we searched MEDLINE and EMBASE for all peer-reviewed articles using keywords including “atypical lymphoplasmacytic and immunoblastic lymphadenopathy” from their inception to December 27, 2023. We also summarized the courses of three cases with a pathological diagnosis of ALPIBP. Nine articles with 52 cases were included. Among the total of 55 cases, including the three from our institution, the median age of the cases was 63.5 years with a female predominance (69.5%). Lymphadenopathy was generalized in 65.6% and regional in 34.4% of cases. RA (24.4%), SLE (24.4%), and autoimmune hemolytic anemia (20.0%), were common clinical diagnoses. A combination of cytotoxic chemotherapy was used in 15.6% of cases due to the suspicion of malignancy. Nodal T-follicular helper cell lymphoma, angioimmunoblastic type, methotrexate-associated lymphoproliferative disorders, and IgG4-related diseases were listed as important diseases that need to be pathologically differentiated from ALPIBP. This review summarizes the current understanding of the characteristics of ALPIBP. Given that underrecognition of ALPIBP could lead to overdiagnosis of hematological malignancy and unnecessary treatment, increased awareness of the condition in pathologists and clinicians is crucial.

Patients with refractory or relapsed (R/R) large B-cell lymphoma (LBCL) refractory to first-line chemotherapy or with early relapse have poor outcomes. While chimeric antigen receptor (CAR) T-cell therapy has impressive efficacy after two or more lines of chemotherapy, it’s still uncertain if these outcomes remain consistent in the context of third-line CAR T-cell therapy. We conducted a retrospective study of 107 R/R LBCL patients. Patients with relapse 12 months or more after their first-line chemoimmunotherapy (late failure: n = 25) had significantly longer overall survival (OS) than patients with refractory disease or relapse within 12 months (early failure: n = 82) (median OS: not achieved vs. 18.4 months; P < 0.001). Among patients who proceeded to autologous hematopoietic stem-cell transplantation (auto-HSCT), those with late failure had significantly longer event-free survival (EFS) than those with early failure (median EFS: 26.9 vs. 3.1 months; P = 0.012). However, no significant difference in EFS was detected among patients who underwent CAR T-cell therapy (median EFS: not reached vs. 11.8; P = 0.091). Cox regression with restricted cubic spline demonstrated that timing of relapse had significant impact on EFS in patients with auto-HSCT but not in patients with CAR T-cell therapy. Of patients who were scheduled for CAR T-cell therapy, those with late failure were significantly more likely to receive CAR T-cell therapy than those with early failure (90% vs. 57%; P = 0.008). In conclusion, patients with early failure still experienced poor outcomes after the approval of third-line CAR T-cell therapy.

The increasing number of treatment options for patients with mantle cell lymphoma (MCL) and chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) in Japan underscores the critical need to comprehend their treatment preferences. In this study, individual semi-structured interviews with 20 Japanese patients with diagnosis of MCL or CLL/SLL were conducted and qualitatively analyzed to elicit concepts important for patients regarding treatment selection. Although effectiveness and safety were imperative for treatment selection, convenience and quality of life were also reported as important attributes. Over the course of their disease journey, patients reported diverse and changing preferences in terms of treatment characteristics. Additionally, there was a discrepancy between their desired and actual levels of involvement in shared decision-making with physicians about treatment choices. Optimal personalized care for better outcomes of patients with MCL and CLL/SLL hinges on healthcare professionals acknowledging individual patient needs and preferences within their cultural, societal and personal context.

Duodenal type follicular lymphoma (DFL), a rare entity of follicular lymphoma (FL), is clinically indolent and is characterized by a low histological grade compared with nodal follicular lymphoma (NFL). Our previous reports revealed that DFL shares characteristics of both NFL and mucosa-associated lymphoid tissue (MALT) lymphoma in terms of clinical and biological aspects, suggesting its pathogenesis may involve antigenic stimulation. In contrast to NFL, the genomic methylation status of DFL is still challenging. Here, we determined the methylation profiles of DNAs from patients with DFL (n = 12), NFL (n = 10), duodenal reactive lymphoid hyperplasia (D-RLH) (n = 7), nodal reactive lymphoid hyperplasia (N-RLH) (n = 5), and duodenal samples from normal subjects (NDU) (n = 5) using methylation specific PCR of targets previously identified in MALT lymphoma (CDKN2B/P15, CDKN2A/P16, CDKN2C/P18, MGMT, hMLH-1, TP73, DAPK, HCAD). DAPK1 was frequently methylated in DFL (9/12; 75%), NFL (9/10; 90%), and D-RLH (5/7; 71%). CDKN2B/P15 sequences were methylated in six DFL samples and in only one NFL sample. Immunohistochemical analysis showed that p15 expression inversely correlated with methylation status. Genes encoding other cyclin-dependent kinase inhibitors (CDKN2A/P16, CDKN2C/P18) were not methylated in DFL samples. Methylation of the genes of interest was not detected in DNAs from D-RLH, except for DAPK1, and the difference in the extent of methylation between NDU and D-RLH was statistically significant (P = 0.013). Our results suggest that D-RLH serves as a reservoir for the development of DFL and that methylation of CDKN2B/P15 plays an important role in this process.

In the new WHO classifications of haematolymphoid tumours (WHO-HAEM5), classic Hodgkin lymphoma (cHL) is categorized into B-cell lymphoid proliferations and lymphomas. Although the majority of Hodgkin Reed-Sternberg (HRS) cells are of germinal center B-cell origin with some defects of B-cell transcription factors, they rarely express T-cell antigens or cytotoxic molecules. Clonality analyses on cHL samples using BIOMED-2 have been reported by several groups; however, those studies were only focused on Ig regions, including IgH, Ig-kappa, and Ig-lambda, and TCR-γ clonality analysis of cHL has not yet been explored. Here, we investigated TCR-γ gene rearrangement for one hundred cases using a PCR-based method. Four of one hundred (4%) cases showed TCR-γ clonal peaks. Of these, three were at an advanced stage and one patient died of the disease. To clarify whether HRS cells showed T-cell clonality or not, we performed PCR analysis using DNAs of microdissected HRS cells. Three samples showed identical clonal peaks with bulk specimens. Our results indicate that cHL is a heterogeneous disease of mainly B-cell and rarely T-cell origin with a special phenotype. Further molecular studies are warranted.

Follicular lymphoma (FL) is a common type of B-cell lymphoma, accounting for about 20% of all lymphomas. Although FL is primarily characterized by an indolent clinical course, histological transformation (HT) remains one of the significant challenges in managing patients with FL. Here, we present a case of FL with partial large-cell transformation due to Epstein-Barr Virus (EBV) arising in a 50-year-old Japanese woman with no known immunodeficiency. Immunohistochemical studies revealed that medium-sized FL cells expressed CD20, CD10, BCL2, and BCL6, whereas large cells were positive for CD20, and MUM1. In situ hybridization (ISH) revealed large cells to be positive for EBV-encoded small RNA (EBER) and further immunohistochemical investigation demonstrated EBER+ cells to express latent membrane protein 1 (LMP1). The Ki-67 index was about 30% in FL cells, and over 70% in large cells. Fluorescence in situ hybridization for BCL2 combined with EBER-ISH identified BCL2 rearrangement in both EBV-infected large cells and EBV-uninfected FL cells, suggesting these two components were clonally related. These findings indicate that EBV contributes to the transformation of FL. As far as the authors could find, only four previous cases of FL development to EBV-positive aggressive lymphoma have been reported. Further studies are needed to clarify the role of EBV in the HT of FL.

Plasmablastic myeloma (PBM) is an uncommon and aggressive morphologic variant of multiple myeloma (MM). The neoplastic immature cells exhibit diverse morphology, posing a diagnostic challenge. The diagnostic criteria for PBM include the identification of ≥ 2% plasmablasts in the bone marrow aspirate. This case describes the incidental finding of a light-chain multiple myeloma (LCMM) transformed into PBM, a phenomenon not previously reported.