INTRODUCTION: The incidental finding of pituitary microadenomas (PmAs) is increasingly common due to the widespread use of MRI. To date, no comprehensive volumetric analyses of PmAs growth patterns have been conducted. A greater understanding of how these lesions progress could influence an array of management strategies, including frequency of imaging and the use of surgical versus conservative medical intervention. METHODS: Patients who underwent = 2 pituitary MRIs for suspected PmAs were identified retrospectively across 4 referral centers worldwide. Patient demographics, presenting symptoms, clinical variables, MRIs, and treatment course were collected and analyzed. RESULTS: A total of 447 patients (Male = 126; 28.2%) referred to the 4 centers from 2003 to 2022 were identified. Median age at first MRI was 43 years [IQR 32–54]. Median number of MRIs per patient was 3 [IQR 2–5] and median follow-up time was 55 months [IQR 29–100]. 300 PmAs (67.1%) were solid, 102 (22.8%) were cystic, 47 (10.5%) were uncertain, and 24 (5.4%) were mixed. At baseline, median suspected tumor volume was 45 mm 3 [15–103]. 77 patients (17.2%) presented with subclinical hyperpituitarism, most often hyperprolactinemia, while 67 (15.0%) experienced hypopituitarism such as hypogonadism, hypothyroidism, and growth hormone deficiency. During follow-up, new onset hyperpituitarism was detected in 20 patients (4.5%) along with hypopituitarism in 9 (2.0%). During the study period, 225 patients (50.3%) had no change in suspected PmA growth, 144 (32.2%) had a decreased size, and 101 (22.6%) had an increased size. 80 patients (17.9%) received medical therapy and 48 (10.7%) underwent transsphenoidal surgery. CONCLUSIONS: With the forthcoming volumetric analysis, we hope to gain further insights into predictors of long-term volumetric evolution of PmAs to improve patient management.

Neural-tumor interactions drive glioma growth as evidenced in preclinical models, but clinical validation is limited. We present an epigenetically defined neural signature of glioblastoma that independently predicts patients' survival. We use reference signatures of neural cells to deconvolve tumor DNA and classify samples into low- or high-neural tumors. High-neural glioblastomas exhibit hypomethylated CpG sites and upregulation of genes associated with synaptic integration. Single-cell transcriptomic analysis reveals a high abundance of malignant stemcell-like cells in high-neural glioblastoma, primarily of the neural lineage. These cells are further classified as neural-progenitor-cell-like, astrocyte-like and oligodendrocyte-progenitor-like, alongside oligodendrocytes and excitatory neurons. In line with these findings, high-neural glioblastoma cells engender neuron-to-glioma synapse formation in vitro and in vivo and show an unfavorable survival after xenografting. In patients, a high-neural signature is associated with decreased overall and progression-free survival. High-neural tumors also exhibit increased functional connectivity in magnetencephalography and resting-state magnet resonance imaging and can be detected via DNA analytes and brain-derived neurotrophic factor in patients' plasma. The prognostic importance of the neural signature was further validated in patients diagnosed with diffuse midline glioma. Our study presents an epigenetically defined malignant neural signature in high-grade gliomas that is prognostically relevant. High-neural gliomas likely require a maximized surgical resection approach for improved outcomes.

Introduction: The diagnosis of pituitary microprolactinomas is often obscured by relatively low levels of elevated prolactin compared to macroprolactinomas. This may lead to varying patterns of medical therapy versus observation. We sought to correlate prolactin levels in suspected microprolactinomas with tumor volumes and clinical outcomes.

The longitudinal transition of phenotypes is pivotal in glioblastoma treatment resistance and DNA methylation emerged as an important tool for classifying glioblastoma phenotypes. We aimed to characterize DNA methylation subclass heterogeneity during progression and assess its clinical impact. Matched tissues from 47 glioblastoma patients were subjected to DNA methylation profiling, including CpG-site alterations, tissue and serum deconvolution, mass spectrometry, and immunoassay. Effects of clinical characteristics on temporal changes and outcomes were studied. Among 47 patients, 8 (17.0%) had non-matching classifications at recurrence. In the remaining 39 cases, 28.2% showed dominant DNA methylation subclass transitions, with 72.7% being a mesenchymal subclass. In general, glioblastomas with a subclass transition showed upregulated metabolic processes. Newly diagnosed glioblastomas with mesenchymal transition displayed increased stem cell-like states and decreased immune components at diagnosis and exhibited elevated immune signatures and cytokine levels in serum. In contrast, tissue of recurrent glioblastomas with mesenchymal transition showed increased immune components but decreased stem cell-like states. Survival analyses revealed comparable outcomes for patients with and without subclass transitions. This study demonstrates a temporal heterogeneity of DNA methylation subclasses in 28.2% of glioblastomas, not impacting patient survival. Changes in cell state composition associated with subclass transition may be crucial for recurrent glioblastoma targeted therapies.

Background H3 K27M-mutated gliomas were first described as a new grade 4 entity in the 2016 World Health Organization classification. Current studies have focused on its typical appearance in children and young adults, increasing the need to better understand the prognostic factors and impact of surgery on adults. Here, we report a multicentric study of this entity in adults.Methods We included molecularly confirmed H3 K27M-mutated glioma cases in patients >= 18 years diagnosed between 2016 and 2022. Clinical, radiological, and surgical features were analyzed. Univariate and multivariate analyses were performed to identify prognostic factors.Results Among 70 patients with a mean age of 36.1 years, the median overall survival (OS) was 13.6 +/- 14 months. Gross-total resection was achieved in 14.3% of patients, whereas 30% had a subtotal resection and 54.3% a biopsy. Tumors located in telencephalon/diencephalon/myelencephalon were associated with a poorer OS, while a location in the mesencephalon/metencephalon showed a significantly longer OS (8.7 vs. 25.0 months, P = .007). Preoperative Karnofsky-Performance Score (KPS) <= 80 showed a reduced OS (4.2 vs. 18 months, P = .02). Furthermore, ATRX loss, found in 25.7%, was independently associated with an increased OS (31 vs. 8.3 months, P = .0029). Notably, patients undergoing resection showed no survival benefit over biopsy (12 vs. 11 months, P = .4006).Conclusions The present study describes surgical features of H3 K27M-mutated glioma in adulthood in a large multicentric study. Our data reveal that ATRX status, location and KPS significantly impact OS in H3 K27M-mutated glioma. Importantly, our dataset indicates that resection does not offer a survival advantage over biopsy.

Prolactinoma account to the most common pituitary adenomas and current therapy regime constitutes of dopamine agonist therapy (DA) and surgery in selected cases [17]. Due to tumor fibrosis induced by previous DA therapy, surgical removal can be challenging though. Therefore, this study investigates how preoperative DA usage influences perioperative treatment and surgical outcome in prolactinoma and aims to ascertain whether a specific subgroup of prolactinoma patients could derive greater benefit from exclusive surgical intervention. We retrospectively analyzed n = 159 surgically treated and histologically confirmed prolactinomas in the sella region from 2013–2022 in our institution. Clinical, radiological and surgical features were analyzed. Univariate and multivariate analyses were performed. Out of total of 159 prolactinoma patients, 83.6

Pituitary neuroendocrine tumors (PitNETs) are classified according to cell lineage, which requires immunohistochemistry for adenohypophyseal hormones and the transcription factors (TFs) PIT1, SF1, and TPIT. According to the current WHO 2022 classification, PitNETs with co-expression of multiple TFs are termed "plurihormonal". Previously, PIT1/SF1 co-expression was prevailingly reported in PitNETs, which otherwise correspond to the somatotroph lineage. However, little is known about such tumors and the WHO classification has not recognized their significance. We compiled an in-house case series of 100 tumors, previously diagnosed as somatotroph PitNETs. Following TF staining, histopathological features associated with PIT1/SF1 co-expression were assessed. Integration of in-house and publicly available sample data allowed for a meta-analysis of SF1-associated clinicopathological and molecular features across a total of 270 somatotroph PitNETs. The majority (74%, 52/70) of our densely granulated somatotroph PitNETs (DGST) unequivocally co-expressed PIT1 and SF1 (DGST-PIT1/SF1). None (0%, 0/30) of our sparsely granulated somatotroph PitNETs (SGST) stained positive for SF1 (SGST-PIT1). Among DGST, PIT1/SF1 co-expression was significantly associated with scarce FSH/LH expression and fewer fibrous bodies compared to DGST-PIT1. Integrated molecular analyses including publicly available samples confirmed that DGST-PIT1/SF1, DGST-PIT1 and SGST-PIT1 represent distinct tumor subtypes. Clinicopathological meta-analyses indicated that DGST-PIT1 respond more favorably towards treatment with somatostatin analogs compared to DGST-PIT1/SF1, while both these subtypes show an overall less aggressive clinical course than SGST-PIT1. In this study, we spotlight that DGST with co-expression of PIT1 and SF1 represent a common, yet underrecognized, distinct PitNET subtype. Our study questions the rationale of generally classifying such tumors as "plurihormonal", and calls for a refinement of the WHO classification. We propose the term "somatogonadotroph PitNET".

Abstract Brain metastases are the most rapidly emerging entity in neuro-oncology. Given the decisive role of immunotherapy, the immune crosstalk between the blood circulation and the brain tumor requires deeper investigation, especially in light of recent data showing that T cells might be trapped in the bone marrow during the metastasis process. We analyzed the immune profile in the peripheral blood and in the bone marrow in a cohort of 40 patients with brain metastasis using flow cytometry. Our results show a global decrease in the proportion of CD3+ T cells in the peripheral blood of patients with brain metastases when compared to healthy donors (HD). CD4+ T cells were more affected by the presence of brain metastases than CD8 cells, with a significant decrease in Tregs, Th1 and Th2 helper cell populations. The proportion of naïve CD4 T cells with low expression of CXCR3 and CD127 is decreased in tumor, while a subpopulation of naïve as well as central memory CD4CM with high expression of PD1 is increased in brain metastasis patients compared to HD. Additionally, we noticed an increase in the proportion of B cells in the patient’ blood, together with a decrease in non-classical CD86+ monocytes compared to HD. The NK cell population was also affected with a significant depletion of mature NK CD57+ in the blood of patients with brain metastases. In the bone marrow, we found an increase in the proportion of senescent CD4CM CD57+ in patients with NSCLC brain metastasis, while the proportion of CD4CM CXCR3+ was significantly decreased compared to HD. Taken together, our data show that brain metastases profoundly affect the phenotype and abundance CD4+ T cells in the periphery and bone marrow, thus interfering with the primary T cell population orchestrating the tumor-specific immune response.

Interactions of neural cells with glioma cells drive tumor growth. In this study, we identified an epigenetically-defined, malignant neural signature of IDH-wildtype glioblastoma (GBM) that significantly influenced patients’ outcome. We used DNA methylation-based reference signatures of neural cells to deconvolve 1.058 primary patient GBM samples. Samples were classified based on the neural reference signature and annotated as low or high neural GBM. A high neural GBM was linked to hypomethylation of CpG sites associated with invasiveness, neuron-to-glioma-interactions, and transsynaptic signaling. Through spatially resolved, single cell transcriptomic and proteomic profiling, we discovered a correlation between the high neural signature and the upregulation of early development programs in OPC and NPC-like cells. These traits were accompanied by diminished immune infiltration and immunological response, further highlighting the distinctive neural-like nature of GBM. High neural GBM demonstrated increased connectivity as evidenced by magnetoencephalography and resting state magnet resonance imaging. Spatiotemporal tumor sampling showed a homogeneous and stable neural signature in newly diagnosed and recurrent GBM. In newly diagnosed GBM, a high neural signature correlated with decreased survival in 306 patients (median OS 15.0 versus 20.0 months, p< 0.001). Patient-derived xenograft models corroborated the aggressive nature of high neural GBM, showing a significantly reduced median OS of 58 days compared to 73 days (p< 0.01). These high neural GBM xenografts also exhibited an elevated tumor burden and an increase in neuron-glioma synapse formation. Consideration of the extent of resection showed a dependency on the neural subgroup as high neural GBM had an increased benefit from a complete contrast enhancing tumor removal when compared to low neural GBM. As a preoperative biomarker, the concentration of BDNF was increased in serum of high neural GBM patients (p < 0.01). Overall, we present an epigenetically-defined malignant neural signature in GBM that is associated with an unfavorable patient survival.

H3 K27M-mutant glioma were first described as a new grade IV entity in the 2016 WHO classification. Current studies have focused on its common pediatric appearance, increasing the need to better understand this entity in adults. Here we report a multicentric, retrospective analysis of 70 diffuse midline glioma in adults. We included molecularly confirmed H3K27M-mutant glioma in patients >18 years of age between 2015-2022. Clinical-, radiological- and surgical features were analyzed. Univariate and multivariate analyses were then performed to identify prognostic factors. The study was approved by the ethics committee (PV4904). Overall, 70 patients were identified, with a mean age of 36.13 years at the initial diagnosis. Median overall survival was 13.62 + 14 months. H3K27M-mutated glioma showed a midline involvement in 61.4%. Clinically, obstructive hydrocephalus was observed in almost half of the patients (46.3%). Gross total resection (GTR) was achieved in 14.5% of all patients. 30.4% had a subtotal resection (STR), and 55.1% received a biopsy. Intraoperative cryo-section resulted in low-grade glioma in 25%, high-grade glioma in 63.9% and no tumor in 11.1%. Tumors located in telencephalon/diencephalon/myelencephalon were associated with a poorer OS, while a location site in the mesencephalon/metencephalon showed a significantly longer survival (8.3 vs. 16.2 months, p = 0.009). Preoperative Karnofsky Performance Score (KPS) below 80 showed a reduced OS (6 vs. 11.24 months, p = 0.03). Patients, who received resection (GTR/STR) showed no significant survival benefit compared with biopsied patients (9.6 vs. 8 months, p = 0.4817). The present study describes surgical features of DMG with H3K27M mutation in one of the most extensive multicentric studies to date in adult patients. Our data show that location and preoperative KPS impact OS significantly in DMG. Furthermore, in our dataset resection of K27M-mutated glioma provided no significant survival benefit compared with biopsy.

Abstract Immune checkpoint therapy has been shown to be effective in several types of cancer, and tumor-directed immune activation is also a promising strategy in glioblastoma (GBM) patients. Our goal was to discover alterations in the circulating immunome of GBM patients and other cerebral tumor entities to identify soluble immune biomarkers and novel therapeutic targets. We analyzed 30 markers in plasma of 208 patients and healthy donors, using bead-based multiplex assays and flow cytometry. In a smaller cohort we further applied a high-sensitivity discovery biomarker platform with 368 markers. We included patients with 1) primary GBM (n=68), 2) recurrent GBM (n=25), 3) cerebral metastases (NSCLC, n=61; breast cancer, n=19), 4) meningioma (n=15) as well as 5) healthy donors (HD, n=20). We detected a distinct immune signature in the peripheral blood of patients with GBM, which was defined by an increased prevalence of soluble immune checkpoint markers (sCD27, sPD-L2, sGal-9), whereas soluble chemokines (CX3CL, CXCL12) were underrepresented. This signature was similar in primary and recurrent GBM, but differed markedly from other cerebral tumor entities as well as from HD. Primary GBM, but not their recurrent counterparts, additionally exhibited increased levels of neurotrophic factors (BDNF, b-NGF) and signs of immune activation with significantly increased levels of IL-18. The biomarker discovery platform further identified 76 proteins that were specifically regulated in GBM compared to HD, offering the potential to serve as biomarkers for disease activity. GBM patients with higher levels of BDNF displayed a significantly shorter survival than patients with lower levels (9.33 vs. 21.90 months; p=0.0001). Likewise patients with high concentrations of VEGF survived significantly shorter than those with low concentrations (12.97 vs. 21.90 months, p=0,0166). Taken together, we were able to delineate a specific immune profile of soluble markers in GBM patients compared to other cerebral tumor entities and to healthy individuals.

Microscopic and endoscopic transsphenoidal surgeries represent the standard treatment for Cushing’s disease (CD). At our institution a new exoscopic approach was implemented. After proof of the general use for transsphenoidal pituitary surgery, the aim of this study was to compare the exoscopic 4K3D video microscope with the microscopic transsphenoidal surgery for patients with CD. We conducted a retrospective analysis on 388 patients with CD treated in our medical center via microscopic transsphenoidal surgery (MTS) between January 2008 and July 2019 or via exoscopic transsphenoidal surgery (ExTS) between May 2019 and May 2021. Parameters investigated included histology, pre- and postoperative MRI with tumor size, pre- and postoperative ACTH and cortisol levels, duration of surgery, perioperative and postoperative complications as well as clinical outcome. Patients who underwent ExTS in CD experienced a lower incidence of SIADH/diabetes insipidus (p = 0.0164), a higher rate of remission (p = 0.0422), and a shorter duration of surgery (p < 0.0001), compared to MTS. However, there was no significant difference regarding new postoperative pituitary insufficiency and intraoperative CSF space opening. We found that ExTS had multiple benefits compared to MTS for tumor resection in case of CD. These results are in line with our previous publication on the general applicability of an exoscope in pituitary surgery. To our knowledge, this is the first clinical study proving the superiority of ExTS in CD. These results are promising, nevertheless further studies comparing exoscopic with the endoscopic approach are necessary to finally evaluate the utility of the new technique.

Cancer is a systemic disease. Due to the exceedingly rare occurrence of metastasis of cerebral glioma, systemic alterations have, however, not been considered to play a major role in disease progression of glioma. T cells orchestrate the adaptive immune response in an antigen-specific, cytokine mediated manner. The aim of our study was to investigate how cerebral glioma impacts systemic T cell immunobiology. We performed gene expression profiling of peripheral blood T cells in patients with IDHwt glioblastomas as well as in a murine glioma model. In addition, we analyzed the levels of soluble immune biomarkers in patient blood and performed flow-cytometric phenotyping of human peripheral blood CD3+ T cells. We discovered a significant skewing of peripheral T cell phenotypes in IDHwt glioblastoma patients compared to healthy donors (HD), showing CD4+ TH1 expansion and reduced numbers of T follicular helper cells (TFH), TH1* and mucosa associated invariant T (MAIT) cells, while TH2 and TH17 percentages remained stable. Interestingly, peripheral memory CD4+ T cells exhibited reduced Fas and PD-1 expression, while CD8 T cells were primarily affected in the non-memory CD45RA+ compartment, displaying reduced numbers of CD8+ CD127+ CD27+ cells. Compared to healthy individuals, GBM patients had significantly increased levels of soluble CD27 while levels of soluble CD25 were reduced (p < 0.05). GSEA and ORA analysis of differentially expressed genes in murine gliomas showed alterations in RNA binding and processing, as well as ribosomal activity in both cell types, indicating systemic modulation in translational- and cell cycle pathways in glioblastoma. Taken together, our results demonstrate a significant skewing of the peripheral T immunobiology in patients with IDHwt gliomas. Our data highlights the importance of considering malignant glioma as a systemic disease that fundamentally alters the immune repertoire in affected patients.