[Interpretation of lymphoid proliferations and lymphomas associated with immune deficiency and dysregulation in the 5th edition WHO classification of haematolymphoid tumours].

The fifth edition of the World Health Organization (WHO) classification of lymphohematopoietic system tumors updated the terminology, types of lesions, diagnostic criteria, nomenclature, and other aspects of lymphoid proliferations and lymphomas associated with immune deficiency and dysregulation. The important updates and main changes in this section were briefly introduced, in order to guide the precise classification of lymphoid proliferations and lymphomas associated with immune deficiency and dysregulation, and standardize pathological reports.

A case of equine multicentric lymphoma: Clinical, microscopical, and molecular findings.

Background: Although relatively uncommon, lymphoma is the most prevalent haematopoietic neoplasia in horses, and multicentric lymphoma remains the most common presentation of the disease. The pathogenesis of equine lymphoma is still poorly understood and the diagnosis is usually confirmed at an advanced stage of the disease, compromising the prognosis. This study investigated the clinical, pathological, and molecular features of a case of equine multicentric lymphoma. Case Description: An apparently healthy 5-year-old crossbreed mare hospitalized at the Centre of Animal Reproduction of Vairão, Portugal, suddenly presented clinical signs of supraorbital oedema and mandibular lymph node enlargement, developing fever, facial oedema, and generalized lymphadenopathy. The mare ended up dying twenty-four days after the first clinical signs due to multisystem organ failure. Haematological and biochemical analyses, necropsy, and microscopic and molecular evaluation of affected tissues were performed. At necropsy, the main findings were multiple multinodular lesions, distributed along the serous surface of oropharynx, trachea, pericardium, gastrointestinal tract, and mesentery. Microscopically, these consisted of solid proliferations of neoplastic round cells that exhibited immunopositivity for CD3 (T cells). Based on these findings, a medium-grade multicentric T-cell lymphoma was diagnosed. Conclusion: There is still very little research regarding the molecular characterization of lymphoma in horses. As an entity itself is quite heterogeneous, it is important to describe the interspecies particularities to understand its development and behaviour.

Non-neoplastic B-cell predominant lymphoid proliferations at the organs exposed to external environment mimicking lymphoma: A potential diagnostic pitfall.

Background: Typically, lymphatic tissue proliferative lesions include either benign lesions or lymphoma. However, not all lymphatic lesions can currently be accurately classified into one category, particularly in mucosal areas that are in contact with the external environment.Aims: To explore the morphology, immunophenotype, and molecular changes of Non-neoplastic B-cell predominant lymphoid proliferations (NBPLP) in pathological areas that are exposed to external surroundings which mimicked lymphoma.Methods and Results: 18 cases of Atypical lymphoid hyperplasia (AtLP)  were retrieved in this study. The biopsy samples were mucosal samples obtained from areas exposed to external surroundings, including intestines, urethra, cervix, tonsils, and tongue. Microscopically, there is a different level of B cell hyperplasia accompanied by morphological atypia. We categorized the morphology into 4 groups: type A (7/18), type B (3/18), type C (3/18), type D (5/18). Part of the AtLP was found positive for BCR gene rearrangement (6/15), and TCR gene rearrangement (1/4). The follow-up period ranged from 14.2 to 70 months. No evidence of lymphoma was found. Therefore, we diagnosed all of the presented cases as NBPLP. We illustrated the key differential points and provided valuable diagnostic experience on each subtype.Conclusions: Areas exposed to the external environment are commonly exposed to antigen and easily present with AtLP of NBPLP, accompanying with positive IGH rearrangement. Therefore, a comprehensive evaluation of macroscopic, morphology, immunophenotype, and molecular diagnostics is required to prevent the overdiagnosis of lymphoma.

[Interpretation of T-cell and NK-cell lymphoid proliferations and lymphomas in the 5th edition of the WHO classification of haematolymphoid tumours].

The 5th edition of the World Health Organization (WHO) classification of haematolymphoid tumours used the hierarchical system to classify T-cell and NK-cell lymphoid proliferations and lymphomas (T/NK-LPD/LYM) based on research advances and clinicopathological characteristics of the diseases. In this edition of classification, tumour-like lesions were included, some tumors were added/deleted, the names or terms of certain diseases were refined, and the diagnostic criteria or subtypes of some diseases were revised. This group of diseases was reintegrated from non-clonal hyperplasia to highly aggressive lymphoma, which would further reflect the nature of T/NK-LPD/LYM and benefit to clinical application.

Programmed Death Ligand 1 (PD-L1) Expression in Lymphomas: State of the Art.

The interaction of programmed death-1 (PD-1) on T lymphocytes with its ligands Programmed Death Ligand 1 (PD-L1) and Programmed Death Ligand 2 (PD-L2) on tumor cells and/or tumor-associated macrophages results in inhibitory signals to the T-cell receptor pathway, consequently causing tumor immune escape. PD-L1/PD-L2 are currently used as predictive tissue biomarkers in clinical practice. Virtually PD-L1 levels expressed by tumor cells are associated with a good response to immune checkpoint blockade therapies targeting the PD-1/PD-L1 axis. These therapies restore T-cell antitumor immune response by releasing T-lymphocytes from the inhibitory effects of tumor cells. Immune checkpoint therapies have completely changed the management of patients with solid cancers. This therapeutic strategy is less used in hematological malignancies, although good results have been achieved in some settings, such as refractory/relapsed classic Hodgkin lymphoma and primary mediastinal large B-cell lymphoma. Variable results have been obtained in diffuse large B-cell lymphoma and T-cell lymphomas. Immunohistochemistry represents the main technique for assessing PD-L1 expression on tumor cells. This review aims to describe the current knowledge of PD-L1 expression in various types of lymphomas, focusing on the principal mechanisms underlying PD-L1 overexpression, its prognostic significance and practical issues concerning the evaluation of PD-L1 immunohistochemical results in lymphomas.

Diagnostics and treatment delay in primary central nervous system lymphoma: What the neurosurgeon should know.

PURPOSE: The gold standard for diagnostics in primary central nervous system lymphoma (PCNSL) is histopathological diagnosis after stereotactic biopsy. Yet, PCNSL has a multidisciplinary diagnostic work up, which associated with diagnostic delay and could result in treatment delay. This article offers recommendations to neurosurgeons involved in clinical decision-making regarding (novel) diagnostics and care for patients with PCNSL with the aim to improve uniformity and timeliness of the diagnostic process for patients with PCNSL. METHODS: We present a mini review to discuss the role of stereotactic biopsy in the context of novel developments in diagnostics for PCNSL, as well as the role for cytoreductive surgery. RESULTS: Cerebrospinal fluid-based diagnostics are supplementary and cannot replace stereotactic biopsy-based diagnostics. CONCLUSION: Histopathological diagnosis after stereotactic biopsy of the brain remains the gold standard for diagnosis. Additional diagnostics should not be a cause of diagnostic delay. There is currently no sufficient evidence supporting cytoreductive surgery in PCNSL, with recent studies showing contradictive data and suboptimal study designs.

The PI3K signaling pathway; from normal lymphopoiesis to lymphoid malignancies.

INTRODUCTION: As a vital mechanism of survival, lymphopoiesis requires the collaboration of different signaling molecules to orchestrate each step of cell development and maturation. The PI3K pathway is considerably involved in the maturation of lymphatic cells and therefore, its dysregulation can immensely affect human well-being and cause some of the most prevalent malignancies. As a result, studies that investigate this pathway could pave the way for a better understanding of the lymphopoiesis mechanisms, the undesired changes that lead to cancer progression, and how to design drugs to solve this issue. AREAS COVERED: The present review addresses the aforementioned aspects of the PI3K pathway and helps pave the way for future therapeutic approaches. In order to access the articles, databases such as Medicine Medline/PubMed, Scopus, Google Scholar, and Science Direct were utilized. The search formula was established by identifying main keywords including PI3K/Akt/mTOR pathway, Lymphopoiesis, Lymphoid malignancies, and inhibitors. EXPERT OPINION: The PI3K pathway is crucial for lymphocyte development and differentiation, making it a potential target for therapeutic intervention in lymphoid cancers. Studies are focused on developing PI3K inhibitors to impede the progression of hematologic malignancies, highlighting the pathway's significance in lymphoma and lymphoid leukemia.

Ageing microenvironment mediates lymphocyte carcinogenesis and lymphoma drug resistance: From mechanisms to clinical therapy (Review).

Cellular senescence has a complex role in lymphocyte carcinogenesis and drug resistance of lymphomas. Senescent lymphoma cells combine with immunocytes to create an ageing environment that can be reprogrammed with a senescence­associated secretory phenotype, which gradually promotes therapeutic resistance. Certain signalling pathways, such as the NF­κB, Wnt and PI3K/AKT/mTOR pathways, regulate the tumour ageing microenvironment and induce the proliferation and progression of lymphoma cells. Therefore, targeting senescence­related enzymes or their signal transduction pathways may overcome radiotherapy or chemotherapy resistance and enhance the efficacy of relapsed/refractory lymphoma treatments. Mechanisms underlying drug resistance in lymphomas are complex. The ageing microenvironment is a novel factor that contributes to drug resistance in lymphomas. In terms of clinical translation, some senolytics have been used in clinical trials on patients with relapsed or refractory lymphoma. Combining immunotherapy with epigenetic drugs may achieve better therapeutic effects; however, senescent cells exhibit considerable heterogeneity and lymphoma has several subtypes. Extensive research is necessary to achieve the practical application of senolytics in relapsed or refractory lymphomas. This review summarises the mechanisms of senescence­associated drug resistance in lymphoma, as well as emerging strategies using senolytics, to overcome therapeutic resistance in lymphoma.

A multicenter proof-of-concept study on deep learning-based intraoperative discrimination of primary central nervous system lymphoma.

Accurate intraoperative differentiation of primary central nervous system lymphoma (PCNSL) remains pivotal in guiding neurosurgical decisions. However, distinguishing PCNSL from other lesions, notably glioma, through frozen sections challenges pathologists. Here we sought to develop and validate a deep learning model capable of precisely distinguishing PCNSL from non-PCNSL lesions, especially glioma, using hematoxylin and eosin (H&E)-stained frozen whole-slide images. Also, we compared its performance against pathologists of varying expertise. Additionally, a human-machine fusion approach integrated both model and pathologic diagnostics. In external cohorts, LGNet achieved AUROCs of 0.965 and 0.972 in distinguishing PCNSL from glioma and AUROCs of 0.981 and 0.993 in differentiating PCNSL from non-PCNSL lesions. Outperforming several pathologists, LGNet significantly improved diagnostic performance, further augmented to some extent by fusion approach. LGNet's proficiency in frozen section analysis and its synergy with pathologists indicate its valuable role in intraoperative diagnosis, particularly in discriminating PCNSL from glioma, alongside other lesions.

Targeting the ubiquitin pathway in lymphoid malignancies.

Ubiquitination and related cellular processes control a variety of aspects in human cell biology, and defects in these processes contribute to multiple illnesses. In recent decades, our knowledge about the pathological role of ubiquitination in lymphoid cancers and therapeutic strategies to target the modified ubiquitination system has evolved tremendously. Here we review the altered signalling mechanisms mediated by the aberrant expression of cancer-associated E2s/E3s and deubiquitinating enzymes (DUBs), which result in the hyperactivation of oncoproteins or the frequently allied downregulation of tumour suppressors. We discuss recent highlights pertaining to the several different therapeutic interventions which are currently being evaluated to effectively block abnormal ubiquitin-proteasome pathway and the use of heterobifunctional molecules which recruit the ubiquitination system to degrade or stabilize non-cognate substrates. This review aids in comprehension of ubiquitination aberrance in lymphoid cancers and current targeting strategies and elicits further investigations to deeply understand the link between cellular ubiquitination and lymphoid pathogenesis as well as to ameliorate corresponding treatment interventions.

Lymphoma presenting as preauricular tumor in unilateral parotid gland agenesis: a case report and review of literature.

BACKGROUND: Parotid gland agenesis is a rare, congenital, usually asymptomatic disorder. Until now, only 24 cases with unilateral, incidentally found, parotid gland agenesis have been described. Here, we present the first reported case of an ipsilateral preauricular neoplasm in a patient with unilateral parotid gland agenesis. During surgery, the position of the greater auricular- and facial nerves was documented. Furthermore, we performed the first sialendoscopy for this rare disorder to assess the number of duct branches, which might be indicative of the abundance of parotid tissue. Moreover, we looked for sialendoscopic characteristic features that could aid in identifying these patients in the ambulatory setting. CASE PRESENTATION: A 50-year-old Greek man presented with a painless, slowly enlarging mass in the right parotid space. Magnetic resonance imaging revealed a complete absence of the right parotid gland without accessory parotid tissue. The right parotid gland was replaced by fatty tissue and the radiologist suggested a benign parotid tumor. Fine needle aspiration was indicative of a reactive lymph node. Sialendoscopy revealed only two branches within the right parotid duct. Surgical resection was performed through a conventional lateral parotidectomy. This revealed typical anatomic position of the greater auricular- and facial nerves despite the parotid tissue agenesis. Histopathology revealed a small lymphocytic lymphoma. CONCLUSIONS: Surgeons should feel confident to resect tumors of the parotid space in patients with parotid gland agenesis. Reduced branching observed during sialendoscopy might indicate parotid gland agenesis. Physicians should be even more cautious than usual with the watch and wait strategy in patients with tumors of parotid gland agenesis, since the probability of a tumor being a benign salivary gland tumor might be lower than usual.

(2,6-Dimethylphenyl)arsonic Acid Induces Apoptosis through the Mitochondrial Pathway, Downregulates XIAP, and Overcomes Multidrug Resistance to Cytostatic Drugs in Leukemia and Lymphoma Cells In Vitro.

Cancer treatment is greatly challenged by drug resistance, highlighting the need for novel drug discoveries. Here, we investigated novel organoarsenic compounds regarding their resistance-breaking and apoptosis-inducing properties in leukemia and lymphoma. Notably, the compound (2,6-dimethylphenyl)arsonic acid (As2) demonstrated significant inhibition of cell proliferation and induction of apoptosis in leukemia and lymphoma cells while sparing healthy leukocytes. As2 reached half of its maximum activity (AC50) against leukemia cells at around 6.3 µM. Further experiments showed that As2 overcomes multidrug resistance and sensitizes drug-resistant leukemia and lymphoma cell lines to treatments with the common cytostatic drugs vincristine, daunorubicin, and cytarabine at low micromolar concentrations. Mechanistic investigations of As2-mediated apoptosis involving FADD (FAS-associated death domain)-deficient or Smac (second mitochondria-derived activator of caspases)/DIABLO (direct IAP binding protein with low pI)-overexpressing cell lines, western blot analysis of caspase-9 cleavage, and measurements of mitochondrial membrane integrity identified the mitochondrial apoptosis pathway as the main mode of action. Downregulation of XIAP (x-linked inhibitor of apoptosis protein) and apoptosis induction independent of Bcl-2 (B-cell lymphoma 2) and caspase-3 expression levels suggest the activation of additional apoptosis-promoting mechanisms. Due to the selective apoptosis induction, the synergistic effects with common anti-cancer drugs, and the ability to overcome multidrug resistance in vitro, As2 represents a promising candidate for further preclinical investigations with respect to refractory malignancies.

Genomic landscape and distinct molecular subtypes of primary testicular lymphoma.

Primary testicular lymphoma (PTL) is a rare lymphoma predominantly occurring in the elderly male population. It is characterized by a limited response to treatment and a heightened tendency towards relapse. Histologically, approximately 90% of PTL cases are classified as diffuse large B-cell lymphomas (DLBCL). Genetic features of PTL were delineated in a limited scope within several independent studies. Some of the articles which analyzed the genetic characterization of DLBCL have incorporated PTL samples, but these have been constrained by small sample sizes. In addition, there have been an absence of independent molecular typing studies of PTL. This report summarizes the common mutational features, copy number variations (CNVs) and molecular typing of PTL patients, based on whole-exome sequencing (WES) conducted on a cohort of 25 PTL patients. Among them, HLA, CDKN2A and MYD88 had a high mutation frequency. In addition, we found two core mutational characteristics in PTL including mutation in genes linked to genomic instability (TP53 and CDKN2A) and mutation in immune-related genes (HLA, MYD88, CD79B). We performed molecular typing of 25 PTL patients into C1 subtype with predominantly TP53 mutations and C2 subtype with predominantly HLA mutations. Notably, mutations in the TP53 gene predicted a poor outcome in most types of lymphomas. However, the C1 subtype, dominated by TP53 mutations, had a better prognosis compared to the C2 subtype in PTL. C2 subtype exhibited a worse prognosis, aligning with our finding that the mechanism of immune escape in PTL was primarily the deletions of HLA rather than PD-L1/PD-L2 alterations, a contrast to other DLBCLs. Moreover, we calculated the tumor mutation burden (TMB) and identified that TMB can predict prognosis and recurrence rate in PTL. Our study underscores the significance of molecular typing in PTL based on mutational characteristics, which plays a crucial role in prognostication and guiding therapeutic strategies for patients.

Diagnosis of cervical lymphoma using a YOLO-v7-based model with transfer learning.

To investigate the ability of an auxiliary diagnostic model based on the YOLO-v7-based model in the classification of cervical lymphadenopathy images and compare its performance against qualitative visual evaluation by experienced radiologists. Three types of lymph nodes were sampled randomly but not uniformly. The dataset was randomly divided into for training, validation, and testing. The model was constructed with PyTorch. It was trained and weighting parameters were tuned on the validation set. Diagnostic performance was compared with that of the radiologists on the testing set. The mAP of the model was 96.4% at the 50% intersection-over-union threshold. The accuracy values of it were 0.962 for benign lymph nodes, 0.982 for lymphomas, and 0.960 for metastatic lymph nodes. The precision values of it were 0.928 for benign lymph nodes, 0.975 for lymphomas, and 0.927 for metastatic lymph nodes. The accuracy values of radiologists were 0.659 for benign lymph nodes, 0.836 for lymphomas, and 0.580 for metastatic lymph nodes. The precision values of radiologists were 0.478 for benign lymph nodes, 0.329 for lymphomas, and 0.596 for metastatic lymph nodes. The model effectively classifies lymphadenopathies from ultrasound images and outperforms qualitative visual evaluation by experienced radiologists in differential diagnosis.

[New classifications of malignant lymphomas - What changes are relevant for practice?] / Neue Klassifikationen maligner Lymphome ­ Welche Änderungen sind für die Praxis relevant?

An internationally uniform lymphoma classification is of fundamental importance for the comparability of clinical studies. There are currently 2 parallel classifications: the "International Consensus Classification" and the WHO-classification. Follicular lymphoma 3B is classified separately as follicular large cell lymphoma in WHO-HAEM5. The diagnostic criteria of lymphoplasmocytic lymphoma (LPL) have been adjusted, both classifications recommend molecular testing for MYD88 and CXCR4 mutations. There are no significant diagnostic changes in aggressive B-cell lymphomas. The ICC classify NLPBL and THRLBCL into the group of large B-cell lymphomas (LBCL). NLPHL/NLPBL-specific therapy must be considered, which differs greatly from the therapy of DLBCL, especially in the early stages. Peripheral T-cell lymphomas are a group of nodal T-cell lymphomas with a TFH phenotype and frequent mutations; peripheral T-cell lymphoma (NOS) is therefore a diagnosis of exclusion. Indolent T-cell lymphomas/lymphoproliferations of the GI tract are rare but must be differentiated from aggressive T-cell lymphomas. The WHO-HAEM5 also includes reactive/non-neoplastic lymph node lesions classified according to B or T cell predominance.

Molecular Pathology of Mature Lymphoid Malignancies.

Lymphoid malignancies are a broad and heterogeneous group of neoplasms. In the past decade, the genetic landscape of these tumors has been explored and cataloged in fine detail offering a glimpse into the mechanisms of lymphomagenesis and new opportunities to translate these findings into patient management. A myriad of studies have demonstrated both distinctive and overlapping molecular and chromosomal abnormalities that have influenced the diagnosis and classification of lymphoma, disease prognosis, and treatment selection.

Estrogen receptor beta expression and role in cancers.

Estrogen drives the growth of some cancers, such as breast cancer, via estrogen receptor alpha (ERα). Estrogen also activates ERß, but whether ERß is expressed and has a role in different cancers is debated. The use of nonspecific antibodies has contributed to the confusion, and this review delves into ERß's controversial role in cancer and focuses on tumor expression that can be supported by non-antibody-dependent assays. We discuss its expression at the transcript level and focus on its potential role in lymphoma, granulosa cell tumors, testicular, and adrenal cancers, emphasizing recent findings and the complexities that necessitate further research.

An analysis of the effects of chronic low dose-rate radiation exposure on cancer focusing on the differences among cancer types.

PURPOSE: The effect of chronic low dose-rate radiation exposure on cancers was investigated by analyzing the data of mice experiments conducted at the Institute for Environmental Sciences (IES). This analysis focuses on the differences between malignant lymphomas and solid cancers. MATERIALS AND METHODS: The analysis is conducted based on the mathematical model introduced in our previous work. The model is expanded to analyze malignant lymphomas and solid cancers separately. Using the expanded model, the effect of chronic low dose-rate radiation on malignant lymphomas and solid cancers are discussed based on their occurrences, progressions, and mortalities. RESULTS: Non-irradiated control group and 20 mGy/day × 400 days irradiated groups are analyzed. The analysis showed that radiation exposure shortened mean life expectancy for both malignant lymphomas and solid cancers (shorter by 89.6 days for malignant lymphomas and 149.3 days for solid cancers). For malignant lymphomas, both the occurrence and the progression are affected by radiation exposure. The mean age at which malignant lymphoma developed in mice was shortened by 32.7 days and the mean progression period was shortened by 57.3 days. The occurrence of solid cancer is also affected by radiation exposure, wherein the mean age at which solid cancer develops was shortened by 147.9 days. However, no significant change in progression period of solid cancers was seen in the analysis. CONCLUSIONS: The analysis showed that the occurrence and mean lifespan are affected in both malignant lymphomas and solid cancers. The shortening of the progression period is only seen in malignant lymphoma, no significant change was observed in solid cancers.

High yield killing of lymphoma cells by anti-CD22 CAR-NK cell therapy.

Chimeric antigen receptors (CARs) offer a promising new approach for targeting B cell malignancies through the immune system. Despite the proven effectiveness of CAR T cells targeting CD19 and CD22 in hematological malignancies, it is imperative to note that their production remains a highly complex process. Unlike T cells, NK cells eliminate targets in a non-antigen-specific manner while avoiding graft vs. host disease (GvHD). CAR-NK cells are considered safer than CAR-T cells because they have a shorter lifespan and produce less toxic cytokines. Due to their unlimited ability to proliferate in vitro, NK-92 cells can be used as a source for CAR-engineered NK cells. We found that CARs created from the m971 anti-CD22 mAb, which specifically targets a proximal CD22 epitope, were more effective at anti-leukemic activity compared to those made with other binding domains. To further enhance the anti-leukemic capacity of NK cells, we used lentiviral transduction to generate the m971-CD28-CD3ζ NK-92. CD22 is highly expressed in B cell lymphoma. To evaluate the potential of targeting CD22, Raji cells were selected as CD22-positive cells. Our study aimed to investigate CD22 as a potential target for CAR-NK-92 therapy in the treatment of B cell lymphoma. We first generated m971-CD28-CD3ζ NK-92 that expressed a CAR for binding CD22 in vitro. Flow cytometric analysis was used to evaluate the expression of CAR. The 7AAD determined the cytotoxicity of the m971-CD28-CD3ζ NK-92 towards target lymphoma cell lines by flow cytometry assay. The ELISA assay evaluated cytokine production in CAR NK-92 cells in response to target cells. The m971-CD28-CD3ζ NK-92 cells have successfully expressed the CD22-specific CAR. m971-CD28-CD3ζ NK-92 cells efficiently lysed CD22-expressing lymphoma cell lines and produced large amounts of cytokines such as IFN-γ and GM-CSF but a lower level of IL-6 after coculturing with target cells. Based on our results, it is evident that transferring m971-CD28-CD3ζ NK-92 cells could be a promising immunotherapy for B cell lymphoma.

Machine learning-based pathomics signature of histology slides as a novel prognostic indicator in primary central nervous system lymphoma.

PURPOSE: To develop and validate a pathomics signature for predicting the outcomes of Primary Central Nervous System Lymphoma (PCNSL). METHODS: In this study, 132 whole-slide images (WSIs) of 114 patients with PCNSL were enrolled. Quantitative features of hematoxylin and eosin (H&E) stained slides were extracted using CellProfiler. A pathomics signature was established and validated. Cox regression analysis, receiver operating characteristic (ROC) curves, Calibration, decision curve analysis (DCA), and net reclassification improvement (NRI) were performed to assess the significance and performance. RESULTS: In total, 802 features were extracted using a fully automated pipeline. Six machine-learning classifiers demonstrated high accuracy in distinguishing malignant neoplasms. The pathomics signature remained a significant factor of overall survival (OS) and progression-free survival (PFS) in the training cohort (OS: HR 7.423, p < 0.001; PFS: HR 2.143, p = 0.022) and independent validation cohort (OS: HR 4.204, p = 0.017; PFS: HR 3.243, p = 0.005). A significantly lower response rate to initial treatment was found in high Path-score group (19/35, 54.29%) as compared to patients in the low Path-score group (16/70, 22.86%; p < 0.001). The DCA and NRI analyses confirmed that the nomogram showed incremental performance compared with existing models. The ROC curve demonstrated a relatively sensitive and specific profile for the nomogram (1-, 2-, and 3-year AUC = 0.862, 0.932, and 0.927, respectively). CONCLUSION: As a novel, non-invasive, and convenient approach, the newly developed pathomics signature is a powerful predictor of OS and PFS in PCNSL and might be a potential predictive indicator for therapeutic response.