Journal of Clinical and Experimental Hematopathology最新文献

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.

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.

We report a case of therapy-related myelodysplastic syndrome (MDS), which developed 9 years after autologous peripheral blood stem cell transplantation (PBSCT) for peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS). A 65-year-old male was diagnosed with PTCL-NOS. After 6 cycles of the CHOP (cyclophosphamide [CPA], doxorubicin, vincristine, and prednisone) regimen, he achieved a first complete response (CR). He relapsed 33 months later and received salvage chemotherapy, which consisted of the CHASE regimen (CPA, high-dose cytarabine, dexamethasone, and etoposide). During the recovery phase of the first cycle of CHASE, his peripheral blood stem cells (PBSCs) were harvested and frozen in 2 bags. After 2 courses of CHASE, he underwent autologous PBSCT, which involved the use of the LEED preconditioning regimen (melphalan, CPA, etoposide, and dexamethasone) and one of the frozen bags. This resulted in a second CR. At 39 months after PBSCT, he relapsed with a tumor in his right arm. After it was resected, he received eight cycles of brentuximab vedotin and 45 Gy of involved-field irradiation concurrently and achieved a third CR. Nine years after autologous PBSCT, he was diagnosed with MDS with excess blasts 2 (MDS-EB-2). His disease progressed to acute myeloid leukemia after 2 courses of azacitidine therapy. He successfully underwent a second autologous PBSCT involving the busulfan and melphalan preconditioning regimen and the other frozen bag, which had been stored for 9 years. He has been in complete cytogenetic remission for 1 year since the second autologous PBSCT.

Methotrexate (MTX)-associated lymphoproliferative disorder (MTX-LPD) is a lymphoproliferative disorder in patients treated with MTX. The mechanism of pathogenesis is still elusive, but it is thought to be a complex interplay of factors, such as underlying autoimmune disease activity, MTX use, Epstein-Barr virus infection, and aging. The NOTCH genes encode receptors for a signaling pathway that regulates various fundamental cellular processes, such as proliferation and differentiation during embryonic development. Mutations of NOTCH1 have been reported in B-cell tumors, including chronic lymphocytic leukemia/lymphoma, mantle cell lymphoma, and diffuse large B-cell lymphoma (DLBCL). Recently, it has also been reported that NOTCH1 mutations are found in post-transplant lymphoproliferative disorders, and in CD20-positive cells in angioimmunoblastic T-cell lymphoma, which might be associated with lymphomagenesis in immunodeficiency. In this study, to investigate the association of NOTCH1 in the pathogenesis of MTX-LPD, we evaluated protein expression of Notch1 in nuclei immunohistochemically in MTX-LPD cases [histologically DLBCL-type (n = 24) and classical Hodgkin lymphoma (CHL)-type (n = 24)] and de novo lymphoma cases [DLBCL (n = 19) and CHL (n = 15)]. The results showed that among MTX-LPD cases, the expression of Notch1 protein was significantly higher in the DLBCL type than in the CHL type (P < 0.001). In addition, among DLBCL morphology cases, expression of Notch1 tended to be higher in MTX-LPD than in the de novo group; however this difference was not significant (P = 0.0605). The results showed that NOTCH1 may be involved in the proliferation and tumorigenesis of B cells under the use of MTX. Further research, including genetic studies, is necessary.

Peritoneal lymphomatosis (PL) is a rare lymphoma-associated condition defined as the dissemination of lymphoma cells in the peritoneum. An 82-year-old man presented with abdominal pain, heartburn, and high fever. Radiological findings, including positron emission tomography-computed tomography (PET-CT), and gastrointestinal fiberscopy, showed diffuse thickening of the peritoneum, omentum, and mesentery; however, no lymphadenopathy, hepatosplenomegaly, or gastrointestinal lesions were observed. Under suspicion of peritonitis carcinomatosa of unknown origin, exploratory laparoscopy was performed that revealed multiple white nodules and masses on the surfaces of the peritoneum, mesentery, and intestinal serosa. The histopathological and cytogenetic findings of the peritoneum revealed high-grade B-cell lymphoma, not otherwise specified, and a gain of MYC by fluorescence in-situ hybridization. The patient was treated with two cycles of R-CHOP therapy, followed by six cycles of dose-adjusted EPOCH-R therapy, and a complete metabolic response was confirmed by PET-CT. Since there are no specific radiological findings to confirm the diagnosis of PL, a histopathological diagnosis is usually required. Most PL exhibit an aggressive lymphoma phenotype and can be cured by appropriate chemotherapy. Therefore, early diagnosis and treatment are desirable.

Primary testicular lymphoma (PTL) frequently relapses in the central nervous system (CNS) despite prophylactic intrathecal chemotherapy, and the outcome for CNS recurrence of PTL is very poor. We report a case of isolated CNS recurrence of bilateral PTL. Our patient achieved complete response (CR) after rituximab-combination chemotherapy for PTL. Approximately five years later, isolated CNS recurrence of PTL occurred. Our patient achieved CR again after high-dose methotrexate therapy and autologous stem cell transplantation (ASCT) with a conditioning regimen of thiotepa and busulfan as a consolidation therapy. The secondary failure of platelet recovery, probably caused by busulfan, occurred after the platelet engraftment. Our patient has remained in CR for over three years. The treatment strategy for CNS recurrence of PTL is mainly whole-brain radiotherapy or high-dose methotrexate-based chemotherapy; however, CNS recurrence of PTL may occur again even after achieving CR. ASCT with a conditioning regimen of thiotepa and busulfan is the optimal consolidation therapy for secondary CNS lymphoma. To the best of our knowledge, this is the second reported case of a patient with isolated CNS recurrence of PTL successfully treated by ASCT with a conditioning regimen of thiotepa and busulfan as a consolidation therapy.

IgG4-related sialadenitis (IgG4-SA) is one of the IgG4-related disease. The histological features of IgG4-SA include dense lymphoplasmacytic infiltrates and fibrosis. This study aimed to reveal the involvement of plasma cells in the development of fibrosis and the mechanism underlying fibrosis in IgG4-SA. Hematoxylin-eosin staining, Azan staining, silver staining, and immunohistochemistry (IHC) were performed on IgG4-SA and chronic sialadenitis specimens, and theses samples were analyzed by image analysis software. Histological spatial analysis was used to analyze the localization of IHC-positive cells and the distances between these cells. In the IgG4-SA group, many secondary lymphoid follicles with germinal centers were found, and many collagen fibers developed around these germinal centers. Collagen fibers composed mainly of type I collagen was abundant at sites away from secondary lymphoid follicles, and reticular fibers composed of type III collagen was abundant near secondary lymphoid follicles. Many FAP⁺ fibroblasts and MUM1⁺ plasma cells were localized near secondary lymphoid follicles. Histological spatial analysis demonstrated that 90.4% of MUM1⁺ plasma cells accumulated within 20 µm of FAP⁺ fibroblasts. Multiple immunofluorescence assays revealed that MUM1⁺ plasma cells expressed platelet-derived growth factor (PDGF) β, and FAP⁺ fibroblasts expressed PDGF receptor (PDGFR) β and pSTAT3 in IgG4-SA. We have shown that fibrosis is localized around secondary lymphoid follicles and that fibroblasts are activated by plasma cells via PDGF/PDGFR signaling in IgG4-SA.

We characterized 5 B-cell tumors carrying t(14;19)(q32;q13) that creates the IGH::BCL3 fusion gene. The patients' ages ranged between 55 and 88 years. Two patients presented with progression or recurrence of B-cell chronic lymphocytic leukemia (B-CLL)/small lymphocytic lymphoma (SLL), two with diffuse large B-cell lymphoma (DLBCL) of non-germinal center B-like phenotype, and the remaining one with composite angioimmunoblastic T-cell lymphoma and Epstein-Barr virus-positive DLBCL. The presence of t(14;19)(q32;q13) was confirmed by fluorescence in situ hybridization (FISH), showing colocalization of 3' IGH and 3' BCL3 probes on der(14)t(14;19) and 5' BCL3 and 5' IGH probes on der(19)t(14;19). One B-CLL case had t(2;14)(p13;q32)/IGH::BCL11A, and 2 DLBCL cases had t(8;14)(q24;q32) or t(8;11;14)(q24;q11;q32), both of which generated IGH::MYC by FISH, and showed nuclear expression of MYC and BCL3 by immunohistochemistry. The IGH::BCL3 fusion gene was amplified by long-distance polymerase chain reaction in 2 B-CLL/SLL cases and the breakpoints occurred immediately 5' of BCL3 exon 1 and within the switch region associated with IGHA1. The 5 cases shared IGHV preferentially used in B-CLL cells, but the genes were unmutated in 2 B-CLL/SLL cases and significantly mutated in the remaining 3. B-cell tumors with t(14;19)(q32;q13) can be divided into B-CLL/SLL and DLBCL groups, and the anatomy of IGH::BCL3 in the latter may be different from that of the former.

We report the case of a 52-year-old male who presented to our hospital with cervical lymphadenopathy. Lymph node biopsy revealed small atypical lymphoid cells positive for CD3 and CD5 and negative for CD56 and Epstein-Barr virus (EBV)-encoded small RNA (EBER) by in situ hybridization. CD4-positive cells and CD8-positive cells were mixed in almost equal numbers. He was diagnosed with peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS). The patient received one cycle of chemotherapy, resulting in severe sepsis. While undergoing treatment in the intensive care unit with an antimicrobial agent and prednisone, ascitic fluid appeared. Abdominal aspiration revealed neutrophil-predominant ascites and microbiological studies revealed Candida albicans. However, ascites did not improve when treated with micafungin for Candida peritonitis. Abdominal aspiration was re-performed, and atypical lymphoid cells that were positive for CD3 and CD56 were detected. EBV-DNA levels in whole blood were significantly elevated. Atypical lymphoid cells were positive for EBER by in situ hybridization and Southern blot analysis showed EBV terminal repeat monoclonal patterns. Bone marrow examination revealed the same atypical lymphoid cells. Therefore, the patient was diagnosed with extranodal natural killer/T-cell lymphoma (ENKTL) with bone marrow involvement 3 months after the diagnosis of PTCL-NOS. Complications associated with PTCL-NOS and ENKTL are rare. PTCL-NOS, chemotherapy, sepsis, and prednisone might have led to immunodeficiency and reactivation of EBV, which might be one of the pathophysiologies for developing ENKTL. Our case indicates that measuring EBV-DNA in the blood is a simple and prompt examination to detect complications of EBV-associated lymphoma.

A 79-year-old man presented with a history of solitary plasmacytoma in the bone 10 years ago. Chemoradiotherapy was effective, and remission was maintained with intermittent treatment at relapse of the bone lesions. One year after the last treatment, a follow-up computed tomography (CT) scan revealed multiple liver masses, and a liver biopsy revealed plasmacytoma. There was no clonal plasma cell infiltration in the bone marrow, and the final diagnosis was solitary plasmacytomas of the liver. Although liver involvement is known in relapsed refractory multiple myeloma, solitary plasmacytoma in the relapsed stage confined to the liver is rare, and all previous reports have been from the initial presentation. To the best of our knowledge, this is the first recurrent case of solitary plasmacytoma of the liver.