Abstract In 5% to 15% of patients with systemic mastocytosis (SM), SM coexists with an associated hematological neoplasm (AHN). Most patients with SM-AHN harbor a KIT mutation, mainly KIT p.D816V, together with other AHN-related genetic alterations; however, limited data exist about the frequency and clinical impact of the coexistence of both types of genetic alterations in the same vs distinct bone marrow (BM) cell compartments. Here, we analyzed 79 patients with SM-AHN classified into patients who (1) displayed distinct unrelated genetic alterations in BM mast cells (MC) and AHN cells (21/79 [27%]); (2) shared the KIT mutation as a first genetic event (24/79 [30%]) involving both BM MC and AHN cells, together with or without AHN-associated alterations restricted to the latter cells; (3) had AHN-associated alterations as a first event (25/79 [32%]) present in both BM MC and AHN cells; and (4) had both alterations involving virtually all SM and AHN cells (9/79 [11%]). Overall, patients with genetically unrelated SM and AHN more frequently showed clinical manifestations associated with SM (ie, anaphylaxis, osteoporosis, and skin lesions) together with prolonged progression-free survival (PFS), whereas those with shared genetic alterations displayed signs of more advanced disease (ie, cytopenias or organomegalies) and shorter PFS and overall survival. Our findings confirm the clinical, genetic, and prognostic heterogeneity of SM-AHN and point to its association with the underlying oncogenic profile of neoplastic MC and AHN cells.

Background The Spanish Network on Mastocytosis (REMA) score was developed to predict clonal mast cell (MC) activation disorders (MCAD) in patients presenting with anaphylaxis without mastocytosis in the skin (MIS) and guide selection of patients for bone marrow (BM) examination. This study reassessed the diagnostic accuracy of the REMA score after 15 years of use and proposes refinements to optimize its predictive value.Methods Overall, 1204 patients with severe MC mediator-related symptoms without MIS referred to the REMA were retrospectively analyzed. All underwent clinical and allergologic evaluation, serum tryptase, BM histology, immunophenotyping, and KIT mutational analysis. REMA scores were calculated and diagnostic accuracy assessed across the score ranges. Multivariable analysis was applied to identify independent predictors and refine prediction.Results Clonal MCAD was diagnosed in 64% of patients who underwent a BM study. Overall, the REMA score showed excellent sensitivity (87%-90%) but limited specificity (34%-35%), with the poorest accuracy in the score 0-2 range. In this subgroup, independent predictors were elevated tryptase without hereditary alpha tryptasemia (OR 5.42, 95% CI 2.86-10.28) and insect venom as trigger (OR 2.18, 95% CI 1.28-3.72). KIT p.D816V in blood, although detected in only 29% of all clonal MCAD cases, allowed identification of additional low-score patients requiring BM evaluation. A refined algorithm combining these predictors improved specificity to 57% while maintaining sensitivity at 86%.Conclusions The REMA score remains highly sensitive for early detection of clonal MCAD presenting without MIS. Incorporation of additional clinical and molecular predictors into an updated diagnostic algorithm enhances specificity and ensures more accurate selection of patients with a REMA score of 0-2 for subsequent BM evaluation.

Pilocytic astrocytomas (PAs) are benign grade 1 gliomas according to the World Health Organization (WHO). They are common in children but rare in adults in whom they may have a worse prognosis. Pediatric PAs are usually associated with dysregulation of the mitogen-activated protein kinase (MAPK) pathway, often involving BRAF alterations such as the KIAA1549::BRAF (K-B) fusion or V600E mutation. We investigated the molecular characteristics of adult PA using gene-targeted next-generation sequencing and specific gene tests, including for K-B fusion, TERT promoter, and FGFR1 hotspot mutations. The most frequent molecular alterations detected involved the MAPK pathway, particularly affecting BRAF and NF1 genes (55%). The prevalence of the K-B fusion (>40%) was higher than previously reported, likely due to challenges in detecting it. We identified molecular alterations in some cases that raised the differential diagnosis of other tumor types, revealing limitations in the 2021 WHO classification for adult PA. After removing other diagnostic types that may mimic PA histology, no adult patients with a diagnosis of PA and K-B fusion died after more than 10 years of mean follow-up. These findings suggest that, similar to pediatric cases, PA in adults may be driven by a single molecular hit, where the K-B fusion is not related to poor outcome.

Glioblastoma (GB), IDH-wildtype (IDH-wt), is the most prevalent primary malignant brain neoplasm in adults. Despite adjuvant therapy, the prognosis for these tumors remains dismal, with a median survival of around 15-18 months. Although rare, extracranial metastases from GB are reported with increasing frequency, likely due to advancements in follow-up, treatments, and improved patient survival. The molecular mechanisms driving the dissemination of GB beyond the central nervous system (CNS) remain elusive, and controversy persists regarding whether these metastasizing tumors possess distinct molecular profiles and whether patients exhibit specific clinical characteristics. We present here a detailed analysis of the molecular evolution of a GB, IDH-wt in a woman in her early forties who subsequently developed extracranial metastases to the liver and spine. This case study provides insights into the mechanisms underlying the dissemination of GB beyond the CNS. By comprehensively reviewing the molecular findings of the literature, we identified frequent TP53 mutations in the tumors at initial diagnosis, as well as evidence of the presence of different clones denoting molecular heterogeneity in those metastasizing tumors. Furthermore, a subset of younger female patients whose tumors at diagnosis present PTEN alterations acquires additional TP53 clonal alterations at recurrence and metastasis. Our findings may contribute to improved prognosis, follow-up, and treatment strategies in GB, IDH-wt patients.

We present a series of 9 follicular lymphomas that progressed/transformed into classical Hodgkin lymphoma (CHL). Three cases of CHL showed a syncytial pattern (SCHL) making the differential diagnosis to Gray zone lymphoma (GZL) challenging. None of these three cases presented in the mediastinum. Based in all molecular data analyzed (BCL2/BCL6 FISH studies, IgH PCR and TNGS with a customized gene panel) we did find clonal relationship between the BCL2-positive FL cases and their CHL components in all cases. The three SCHL/GZL cases showed an activated phenotype according to Hans algorithm, presented the t(14; 18)(q32; q21), two out of three showed B cell markers and all expressed CD30 and p53. Interestingly, we identified three BCL2-negative FL cases with a further diagnosis of CHL expanding the spectrum of these association. In one of these three cases a different mutational profile was found in both the FL and the CHL components. All this data together suggests that CHL associated to BCL2-positive FL could be originated in a common progenitor cell (CPC) that give rise to both FL and CHL, acquiring this last component further genetic events in a linear fashion. On the other hand, no clonal relationship between CHL and BCL2-negative FL could be found, suggesting a fortuity association. Nevertheless, ample series of cases studied with more sensitive techniques are needed to confirm our hypothesis.

We present a series of 9 follicular lymphomas that progressed/transformed into classical Hodgkin lymphoma (CHL). Three cases of CHL showed a syncytial pattern (SCHL) making the differential diagnosis to Gray zone lymphoma (GZL) challenging. None of these three cases presented in the mediastinum. Based in all molecular data analyzed (BCL2/BCL6 FISH studies, IgH PCR and TNGS with a customized gene panel) we did find clonal relationship between the BCL2-positive FL cases and their CHL components in all cases. The three SCHL/GZL cases showed an activated phenotype according to Hans algorithm, presented the t(14;18)(q32;q21), two out of three showed B cell markers and all expressed CD30 and p53. Interestingly, we identified three BCL2-negative FL cases with a further diagnosis of CHL expanding the spectrum of these association. In one of these three cases a different mutational profile was found in both the FL and the CHL components. All this data together suggests that CHL associated to BCL2-positive FL could be originated in a common progenitor cell (CPC) that give rise to both FL and CHL, acquiring this last component further genetic events in a linear fashion. On the other hand, no clonal relationship between CHL and BCL2-negative FL could be found, suggesting a fortuity association. Nevertheless, ample series of cases studied with more sensitive techniques are needed to confirm our hypothesis.

Pilocytic astrocytoma (PA) is a benign grade 1 glioma according to the World Health Organization (WHO). It is frequent in pediatric population, but very rare in adults, where it can be associated with worse prognosis. Molecular features of pediatric PA are associated with dysregulation of the MAPK pathway, most often showing BRAF alterations such as the KIAA1549::BRAF (K-B) fusion or the V600E mutation. Here we analyze the molecular characteristics of adult PA through gene-targeted next-generation sequencing (NGS) and single gene tests (K-B fusion, and TERT promoter and FGFR1 hotspot mutations). In adults, the most frequent molecular alterations detected involved the MAPK pathway, namely affecting with BRAF and NF1 genes (16/29, 55%). Our study reveals that the prevalence of the K-B fusion (44.5%), is higher than what was reported in other adult PA series, probably due to technical difficulties in detecting the fusion. This molecular alteration was not associated with recurrence, but worse outcome was observed in patients with additional alterations, in particular oncogenic ATRX mutations. Furthermore, our results unveiled a subset of cases showing molecular alterations that raise differential diagnosis with other tumor types, thus demonstrating limitations of the current 2021 WHO classification in adult PA. In summary, our study suggests that PA in adults is a single-hit disease, as is the case in the pediatric population.

Follicular lymphoma (FL) is the most frequent indolent lymphoma. Some patients (10%-15%) experience histologic transformation (HT) to a more aggressive lymphoma, usually diffuse large B-cell lymphoma (DLBCL). This study aimed to validate and improve a genetic risk model to predict HT at diagnosis.We collected mutational data from diagnosis biopsies of 64 FL patients. We combined them with the data from a previously published cohort (total n = 104; 62 from nontransformed and 42 from patients who did transform to DLBCL). This combined cohort was used to develop a nomogram to estimate the risk of HT. Prognostic mutated genes and clinical variables were assessed using Cox regression analysis to generate a risk model. The model was internally validated by bootstrapping and externally validated in an independent cohort. Its performance was evaluated using a concordance index and a calibration curve. The clinicogenetic nomogram included the mutational status of 3 genes (HIST1HE1, KMT2D, and TNFSR14) and high-risk Follicular Lymphoma International Prognostic Index and predicted HT with a concordance index of 0.746. Patients were classified as being at low or high risk of transformation. The probability HT function at 24 months was 0.90 in the low-risk group vs 0.51 in the high-risk group and, at 60 months, 0.71 vs 0.15, respectively. In the external validation cohort, the probability HT function in the low-risk group was 0.86 vs 0.54 in the high-risk group at 24 months, and 0.71 vs 0.32 at 60 months. The concordance index in the external cohort was 0.552. In conclusion, we propose a clinicogenetic risk model to predict FL HT to DLBLC, combining genetic alterations in HIST1H1E, KMT2D, and TNFRSF14 genes and clinical features (Follicular Lymphoma International Prognostic Index) at diagnosis. This model could improve the management of FL patients and allow treatment strategies that would prevent or delay transformation.

Analyzed IGH, IGK/L rearrangements. Annotation characteristics

Brain metastases are tumors that arise from a tumor cell originated in another organ rea-ching the brain through the blood. In the brain this tumor cell is capable of growing and invading neighboring tissues, such as the meninges and bone. In most patients a known tumor is present when the brain lesion is diagnosed, although it is possible that the first diagnose is the brain tumor before there is evidence of cancer elsewhere in the body. For this reason, the neurosurgeon must know the management that has shown the grea-test benefit for brain metastasis patients, so treatments can be streamlined and optimized. Specifically, in this document, the following topics will be developed: selection of the cancer patient candidate for surgical resection and the role of the neurosurgeon in the multi-disciplinary team, the importance of immunohistological and molecular diagnosis, surgical techniques, radiotherapy techniques, treatment updates of chemotherapy and immunot-herapy and management algorithms in brain metastases. With this consensus manuscript, the tumor group of the Spanish Society of Neurosurgery (GT-SENEC) exposes the most relevant neurosurgical issues and the fundamental aspects to harmonize multidisciplinary treatment, especially with the medical specialties that are treating or will treat these patients. (c) 2023 Sociedad Espanola de Neurocirugia. Published by Elsevier Espana, S.L.U. All rights reserved.

In the present study, we screened 84 Follicular Lymphoma patients for somatic mutations suitable as liquid biopsy MRD biomarkers using a targeted next-generation sequencing (NGS) panel. We found trackable mutations in 95% of the lymph node samples and 80% of the liquid biopsy baseline samples. Then, we used an ultra-deep sequencing approach with 2 · 10−4 sensitivity (LiqBio-MRD) to track those mutations on 151 follow-up liquid biopsy samples from 54 treated patients. Positive LiqBio-MRD at first-line therapy correlated with a higher risk of progression both at the interim evaluation (HRINT 11.0, 95% CI 2.10–57.7, p = 0.005) and at the end of treatment (HREOT, HR 19.1, 95% CI 4.10–89.4, p < 0.001). Similar results were observed by PET/CT Deauville score, with a median PFS of 19 months vs. NR (p < 0.001) at the interim and 13 months vs. NR (p < 0.001) at EOT. LiqBio-MRD and PET/CT combined identified the patients that progressed in less than two years with 88% sensitivity and 100% specificity. Our results demonstrate that LiqBio-MRD is a robust and non-invasive approach, complementary to metabolic imaging, for identifying FL patients at high risk of failure during the treatment and should be considered in future response-adapted clinical trials.

PURPOSE:To assess the potential value of LiqBio as a complementary tool for diagnosis and surveillance of BCL. METHODS:This prospective multi-center study included 78 patients (25 follicular lymphomas (FL) and 53 large B-cell lymphomas (LBCL)). We performed next-generation sequencing (NGS) of cfDNA LiqBio and paired gDNA tissue biopsies at diagnosis and compared the mutational statuses. Also, through NGS of LiqBio, we identified MRD biomarkers and compared this novel LiqBio-MRD method with PET/CT in detecting MRD at follow-up. RESULTS:We identified mutations in 71% of LiqBio and 95% of tissue biopsies, and found a correlation between variant allele frequency of somatic mutations. Additionally, we identified mutations in 73% of LiqBio from patients with no available tissue samples or no mutations in them. Regarding the utility of LiqBio-MRD as a dynamic monitoring tool, when compared with the PET/CT method, a lower sensitivity was observed for LiqBio-MRD at 92.3% (vs. 100% for PET/CT), but a higher specificity of 91.3% (vs. 86.9% for PET/CT). CONCLUSION:Genetic profiling of tumor cfDNA in plasma LiqBio is a complementary tool for BCL diagnosis and MRD surveillance.

Las metástasis cerebrales (MC) son tumores que se forman a partir de una célula tumoral originada en otro órgano y que a través de la sangre llega al cerebro donde es capaz de crecer e invadir los tejidos vecinos, como meninges y hueso.

Counts and distribution of confirmed and unconfirmed replacement and silent mutations per IGHV gene group and V-subregion. Respective R/S ratios

BACKGROUND: The Red Espanola de Mastocitosis (Spanish Network on Mastocytosis) score (REMAs) and the National Institutes of Health idiopathic clonal anaphylaxis score (NICAS) were developed for more efficient screening of mast cell (MC) clonality in MC activation syndromes. In a limited idiopathic anaphylaxis case series, the NICAS showed higher accuracy compared with the REMAs. OBJECTIVE: To compare the performance of the REMAs against the NICAS in the diagnosis of MC clonality.METHODS: We compared the diagnostic value of the REMAs against the NICAS in 182 patients (63% men, median age 56 years) who presented with anaphylaxis triggered by Hymenoptera venom allergy (45%), drugs (15%), food (11%), idiopathic anaphylaxis (20%), and mixed causes (10%). KIT mutation was assessed in parallel in whole blood and bone marrow (BM) and, when negative, in highly purified BM MC. TPSAB1 was genotyped in a subset of 71 patients. RESULTS: We found higher accuracy and rates of correctly classified patients for the REMAs (82% and 84%) compared with the NICAS (75% and 75%; P = .02 and P = .03, respectively), particularly among men (P = .05), patients with systemic mastocytosis (P = .05), those presenting anaphylaxis owing to any cause featuring urticaria (P = .04), cardiovascular symptoms (P = .02), and/or presyncope (P = .02) and those with a blood-negative/BM-positive KIT mutational profile (P = .002), but not hereditary a-tryptasemiaeassociated genotypes. Combined assessment of the REMAs and KITD816V in blood yielded an overall improved classification efficiency of 86% versus 84% for REMAs.CONCLUSIONS: The combined use of the REMAs and blood detection of KITD816V is recommended, but more sensitive blood-based molecular assays to detect KITD816V are needed. (c) 2022 American Academy of Allergy, Asthma & Immunology (J Allergy Clin Immunol Pract 2023

Recurrent amino acid replacements. Counts and distribution per IGHV gene and V-subregion. Respective physicochemical characteristics of the substitutions

Network of the aligned IGVH1-2*04 CDR3 sub-regions, depicting the emerging patterns

Abstract BACKGROUND Pilocytic astrocytoma (PA) is a rare, grade 1 subtype of glioma. It is most frequent during the first two decades of life, the incidence rate decreasing with age. PAs are usually located in the cerebellum, although they have also been described in other sites. They are circumscribed, solid-cystic, with low cellularity and generally slow-growing tumours with good prognosis in the paediatric age group. PA is associated with MAPK pathway dysregulation, most often showing BRAF gene alterations. PA is very rare in older adults and is associated in some cases with a worse prognosis. In this work we set out to analyse a series of adult PA from a clinical, morphological and molecular point of view. MATERIAL AND METHODS Clinical data were collected from a group of adult patients diagnosed with PA. Nucleic acid extraction was performed by automated extraction and the samples were analysed through a 30-gene targeted panel for gliomas by using Next-Generation Sequencing. Tandem duplication causing fusion of KIAA1549 and BRAF genes (K-B fusion) was analysed by RT-PCR. RESULTS Thirty-four patients were included, with a mean age of 34.4 years (range, 18-57 years). The male/female ratio was 26/8. Mean overall survival was 150.5 months, with more than 10 years of mean follow-up. At the time of the last review, 91% (30/33) of the patients remained alive, while the remaining 9% (3/33) died. Neuroanatomic locations (31 cases) were as follows: cerebrum/lobar 23% (7), cerebellum 39% (12), brainstem 10% (3), ventricle 6% (2), spinal cord 10% (3), optic nerve 13% (4). The K-B fusion was detected in 44% of cases (8/18). Of these, 87.5% (7/8) and 12.5% (1/8) showed fusions involving exons 16:9 and 15:9, respectively. K-B positive cases had a mean age of 40 years. Analyses by NGS revealed mutations in NF1 (15%), BRAF (11%), PDGFRA (11%), EGFR (7%) and PIK3CA (7%). Other variants observed in 4% of cases involved ATRX, CIC, IDH1, KEL, KRAS, MET, MSH6, PTPN11 and RB1. No alterations were detected in 3 of the cases, suggesting that other untested driver alterations could be present. CONCLUSION In this series, no significant differences with childhood PA in the frequency of molecular alterations were observed, in contrast to other gliomas where there are strong differences in the molecular alterations between adult and paediatric tumours. The most common genetic alterations in adult PA involved the MAPK pathway, as previously reported. In contrast to other adult PA studies, the frequency of K-B fusion was similar to that of paediatric PA. Molecular alterations related to an aggressive behaviour or to other glioma types were identified, such as mutations of ATRX, PDGFRA, NF1 or PI3KCA, which can suggest other tumour types. Our results suggest the need for multilayer histological and molecular diagnosis to appropriately manage adult PA.