Journal of Clinical and Experimental Hematopathology最新文献

Kikuchi-Fujimoto disease (KFD), also known as histiocytic necrotizing lymphadenitis, is a rare condition characterized by benign localized lymphadenopathy and clinical symptoms such as fever, sore throat, odynophagia, and leukopenia. Though the etiology of KFD is unknown, this condition is similar to viral infection, including increased infiltration of activated plasmacytoid dendritic cells. KFD exhibits three histological phases that reflect its progression status: proliferative, necrotic, and xanthomatous lesions. The expression loss of pan T-cell markers, such as CD2, CD5, and CD7, of infiltrating T-cells is observed in KFD cases, complicating the distinction from T-cell lymphoma. However, reports on the loss of their expression in KFD have been limited. Furthermore, the precise population of the T-cell subset in KFD is still unclear. Here, we focused on surface markers and transcription factors for T-cell differentiation and analyzed them immunohistochemically in 46 KFD cases. We observed diminished CD5 expression of CD8-positive (CD5_^dim CD8+) T-cells in the proliferative lesion of KFD cases. Furthermore, these CD5_^dim CD8+ T-cells expressed T-BET, a master regulator of type 1 helper T-cells. The upregulation of T-BET and downregulation of CD5 in CD8+ T-cells causes dysregulated activation and proliferation of CD8+ T-cells, potentially contributing to the unique histopathological features of KFD. Recognizing the frequent infiltration of T-BET-positive CD5_^dim CD8+ T-cells in KFD is important for distinguishing it from mature T-cell lymphoma. Our findings suggest that the immune response in KFD shares similarities with viral infections and highlight the importance of characterizing T-BET-positive CD5_^dim CD8+ T-cell populations for understanding KFD pathogenesis.

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.

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.

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.

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.

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.

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.

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.