The value of bone marrow biopsy for staging of patients with primary CNS lymphoma

Discordant lymphoma characterized by the coexistence of diffuse large B-cell lymphoma in the brain and mantle cell lymphoma in the colon, rectum, and bone marrow

We describe a rare case of discordant lymphoma characterized by the coexistence of diffuse large B-cell lymphoma (DLBCL) in the brain and mantle cell lymphoma (MCL) in the colon, rectum, and bone marrow. A 63-year-old male patient with consciousness impairment and gait disturbance was admitted to our institution. Head computed tomography scan and contrast-enhanced magnetic resonance imaging showed a mass in the right temporal lobe and rectal wall thickening. Brain biopsy revealed DLBCL, and bone marrow and rectum biopsy showed MCL. According to a polymerase chain reaction analysis of immunoglobulin heavy-chain gene rearrangements using brain and bone marrow specimens, the two lesions were clonally unrelated lymphomas. After five cycles of R-MPV (rituximab, methotrexate, procarbazine, vincristine) therapy and three cycles of R-ESHAP (rituximab, etoposide, cytarabine, cisplatin, methylprednisolone) therapy, the patient received autologous hematopoietic stem cell transplantation using R-MEAM (rituximab, ranimustine, etoposide, cytarabine, melphalan) regimen after bridging therapy with ibrutinib. In addition, he received whole-brain irradiation at a dose of 40 Gy in 20 fractions as consolidation therapy. He did not relapse within 3 years of transplantation. To the best of our knowledge, this is the first case report of DLBCL and MCL coexistence.

Double-hit primary central nervous system lymphoma with histogenetically proven bone marrow infiltration: a case report and a review of the literature

Double-hit lymphoma (DHL) formerly referred to high-grade B-cell lymphoma with concurrent MYC and BCL2 or BCL6 rearrangements, however, the updated 2022 World Health Organization Classification (5th edition online) excludes those with MYC and BCL 6 rearrangements from the high-grade category. DHL confined to the central nervous system (CNS), known as double-hit primary CNS lymphoma (DH-PCNSL), is rare with poorly understood clinical features. Here, we report a case of a 64-year-old man with multiple brain tumors diagnosed with DH-PCNSL who showed bone marrow (BM) infiltration early in the clinical course. The histological diagnosis was high-grade B-cell lymphoma with MYC and BCL6 rearrangements. Fluorodeoxyglucose positron emission tomography (FDG-PET) revealed no abnormal accumulation except in the CNS. The patient received whole-brain radiotherapy following the failure of high-dose methotrexate. After completion of radiotherapy, the patient developed thrombocytopenia, and BM biopsy showed infiltration of DHL cells, which were not detected by repeated FDG-PET. This is the first report of DH-PCNSL where identical gene rearrangements were confirmed in both the resected CNS tumor and BM tissue. Patients with DH-PCNSL require careful follow-up because they may be at a potential risk of BM infiltration, which may be undetectable by FDG-PET, particularly early in the disease course.

Isolated Hodgkin lymphoma of the intracranial dura: A case report and review of the literature

Primary dural Hodgkin lymphoma (PDHL) is an extremely rare subset of Hodgkin lymphoma (HL). Its existence is controversial, as Hodgkin lymphoma is not traditionally thought to arise from the central nervous system (CNS) or its meninges and only 0.02% of patients with Hodgkin lymphoma have any CNS involvement. We report a case of a 71-year-old Caucasian man who presented with progressive fatigue and sudden onset slurred speech, disorientation, and memory loss. Brain imaging identified a large extra-axial right frontal mass, and he underwent urgent subtotal resection. Pathology and subsequent workup revealed Stage IAE classical Hodgkin lymphoma of the right frontal dura, with no extra-cranial disease or leptomeningeal spread detected. The patient was subsequently treated with ABVD chemotherapy (completed 2.5 of 4 planned cycles) and 36 Gy in 20 fractions of consolidative involved-site radiotherapy (ISRT). He has been followed for 5 years with no clinical or radiological signs of recurrence. This is the second confirmed case of intracranial PDHL reported in the literature, with the longest follow-up for any case of PDHL.

Bone marrow biopsy can be omitted in the diagnostic workup of CNS lymphoma of DLBCL origin: a population-based retrospective study in the PET-CT era

Currently, bone marrow (BM) biopsy (BMB) is recommended in the initial staging of patients with the presumed primary central nervous system (CNS) lymphoma (PCNSL). However, the added value of BMB in the era of positron emission tomography (PET-CT) has been challenged in other lymphoma subtypes. We analyzed BM findings in patients with biopsy-proven CNS lymphoma and a negative PET-CT scan for disease outside CNS. A comprehensive Danish population-based registry search was performed to identify all patients with CNS lymphoma of diffuse large B cell lymphoma (DLBCL) histology with available BMB results and staging PET-CT without systemic lymphoma. A total of 300 patients fulfilled the inclusion criteria. Of them, 16% had a previous history of lymphoma, while 84% were diagnosed with PCNSL. None of the patients had DLBCL in the BM. A minority (8.3%) had discordant BMB findings, mainly low-grade histologies that did not influence treatment choice in any case. In conclusion, the risk of overlooking concordant BM infiltration in patients with CNS lymphoma of DLBCL histology and negative PET-CT scan is negligible. As we did not find any patient with DLBCL in the BMB, our results suggest that BMB can be safely omitted in the diagnostic workup in patients with CNS lymphoma and a negative PET-CT.

Recent advances in the diagnosis and the treatment of primary CNS lymphoma

This review focuses on the recent progress in the management of primary central nervous system lymphoma (PCNSL). Multiomic analyses allowed to better understand the tumorigenesis of PCNSL and to establish a molecular classification with prognostic value that will optimize patient management and guide future targeted approaches. Cooperative clinical trials have demonstrated the feasibility and efficacy, in selected fit patients, of high-dose chemotherapy with autologous stem cell transplantation as post-induction consolidation, that will progressively replace whole brain radiotherapy associated with a much higher risk of delayed neurotoxicity. Several novel treatments have shown efficacy and overall good tolerance in PCNSL patients, such as Bruton's tyrosine kinase (BTK) inhibitors, imids, immune checkpoint inhibitors and chimeric antigen receptor T-cells (CAR-T). This opens promising therapeutic perspectives to improve the current standard treatment, especially for elderly and unfit patients who represent a growing population.

Primary central nervous system lymphoma: a practical guide for neurologists

Primary central nervous system lymphoma is rare, comprising 4% of intracranial neoplasms. Although haematologists or oncologists subsequently manage the condition, it is often neurologists who first make, or at least suspect, the diagnosis. This article reviews the disease, its clinical and radiological features and details the work-up needed to achieve a diagnosis (namely histological or cytological confirmation) and to prepare the patient for treatment. We note the importance of brain biopsy, the role of corticosteroids and the varied treatment options.

Primary CNS lymphoma: update on molecular pathogenesis and therapy

Primary central nervous system lymphoma (PCNSL) is a rare and aggressive form of extra-nodal non-Hodgkin lymphoma that as a brain tumor poses a unique set of challenges in diagnosis and management. With the advent of next-generation sequencing, we review updates in the understanding of its molecular and genomic pathogenesis. We also highlight key issues in management, with a focus on emerging technologies and new biological therapies including monoclonal antibodies, IMiDs, BTK inhibitors, PD-1 inhibitors, and CAR-T therapy. Integration of these approaches will likely enhance induction and consolidation strategies to suppress NF-κB activation and the anti-tumor immune response, while minimizing the often noxious effects of genotoxic approaches.

Analysis of Cellular Heterogeneity in Immune Microenvironment of Primary Central Nervous System Lymphoma by Single-Cell Sequencing

Background

Primary central nervous system lymphoma (PCNSL) is characterized by a lack of specificity and poor prognosis. Further understanding of the tumor heterogeneity and molecular phenotype of PCNSL is of great significance for improving the diagnosis and treatment of this disease.

Methods

To explore the distinct phenotypic states of PCNSL, transcriptome-wide single-cell RNA sequencing was performed on 34,851 PCNSL cells from patients. The cell types, heterogeneity, and gene subset enrichment of PCNSL were identified. A comparison of the PCNSL cells with 21,250 normal human fetal brain (nHFB) cells was further analyzed to reveal the differences between PCNSL and normal sample.

Results

Six cell populations were mainly identified in the PCNSL tissue, including four types of immune cells—B cell, T cell, macrophage and dendritic cell—and two types of stromal cells: oligodendrocyte and meningeal cell. There are significant cellular interactions between B cells and several other cells. Three subpopulations of B cells indicating diffident functions were identified, as well as a small number of plasma cells. Different subtypes of T cells and dendritic cells also showed significant heterogeneity. It should be noted that, compared with normal, the gene expression and immune function of macrophages in PCNSL were significantly downregulated, which may be another important feature of PCNSL in addition to B cell lesions and may be a potential target for PCNSL therapy.