Ameloblastomas are locally aggressive odontogenic tumors that most commonly arise in the mandible and maxilla and often harbor BRAF V600E mutations. While rare extragnathic ameloblastomas have been reported, primary pulmonary cases have not been documented. We identified 3 pulmonary neoplasms with features of ameloblastoma that were submitted for consultation between 2022 and 2025 at 3 academic institutions and performed detailed clinicopathologic and molecular analysis. The tumors presented as 5.4 to 7.3 cm peribronchial solitary lung masses. All resected tumors exhibited a predominant stellate reticulum-like component composed of loosely arranged p40-reactive bland squamoid-to-spindled cells with long intercellular bridges, and streaming and swirling architecture, surrounded by palisaded columnar cells with focal reverse nuclear polarity at the interface with myxoid stroma. All tumors were immunoreactive for BRAF V600E IHC, and BRAF V600E mutations were confirmed by molecular assays, including broad next-generation sequencing on 2 cases. Florid hyperplasia of entrapped pneumocytes initially suggested a biphasic neoplasm, but the absence of BRAF V600E IHC labeling confirmed pneumocyte entrapment. Occult gnathic primary tumors were excluded by subsequent clinical examination, including negative panoramic dental x-rays. No recurrences or metastases have been observed to date. This first series of primary pulmonary ameloblastomas highlights a distinctive tumor with histologic and molecular features identical to gnathic counterparts. We discuss the potential histogenesis of these unusual tumors.
Volatile Anesthetics: A Comprehensive Review of Pharmacology, Delivery Systems, and Safety Considerations for ICU Practitioners
OBJECTIVE: Volatile anesthetics (VAs) are gaining renewed interest as a sedation strategy in the intensive care, offering an alternative to traditional IV agents. VAs provide several pharmacologic advantages, including rapid onset and offset, minimal systemic metabolism, and favorable recovery profiles. Advances in delivery systems enabled the safe and practical administration of volatile agents in the ICU. Thus, we aimed to describe the pharmacology and safety aspects of inhaled agents as well as the systems designed to deliver VAs in the ICU. DATA SOURCES: Relevant literature was identified through PubMed and MEDLINE databases. STUDY SELECTION: Original research, review articles, commentaries, and guidelines addressing safety, efficacy, and use of VAs in adult ICU patients were included. DATA EXTRACTION: Studies were reviewed by the authors, with key findings summarized and organized by pharmacologic properties, delivery systems, and safety domains. DATA SYNTHESIS: VAs are halogenated hydrocarbons whose mechanism of action is not fully understood. Although the CNS is the primary site of action, the end-tidal concentration of exhaled anesthetic is used to monitor clinical effects such as immobility to a noxious stimulus. Inhaled agents have unique pharmacokinetics, minimal metabolisms, and distinct recovery. The side effect profile is also unique, with malignant hyperthermia being the most feared, yet rare complication. Two systems for inhalational sedation delivery are available internationally, with one currently under evaluation in the United States. The systems are composed of a miniature vaporizer, delivery controller, and a monitor. The systems have distinct safety considerations, such as tidal volume limits. CONCLUSIONS: VAs can be used as sedative agents in the ICU. This article comprehensively reviews the pharmacology of VAs along with their safety profile and describes the structure and function of miniature vaporizers currently available on the world market.
Cytogenetics-based Clinical Trajectories in Patients with MRD Negativity Post Autologous Transplant for Multiple Myeloma
Abstract Measurable residual disease (MRD) assessment has become central to risk-adapted treatment strategies in multiple myeloma, yet the prognostic value of MRD negativity following autologous stem cell transplantation (ASCT) across individual high-risk cytogenetic abnormalities (HRCAs) remains unclear. We analyzed 351 newly diagnosed patients who achieved MRD negativity (sensitivity 2.4×10 − 6 ) at Day 100 following ASCT and had baseline cytogenetic data available. Median follow-up was 50.4 months. Standard-risk cytogenetics were present in 46% (n = 162), while 34% (n = 118) had one HRCA and 20% (n = 71) had ≥ 2 HRCAs. Despite uniform MRD negativity, several HRCAs continued to confer inferior progression-free survival (PFS). Compared with the standard-risk group (4-year PFS 84%), patients with del(17p), 1q21+, t(4;14), or MAF translocations [t(14;16)/t(14;20)] had significantly lower 4-year PFS rates: 56% (HR 2.89; p = 0.0001), 60% (HR 2.46; p = 0.0001), 43% (HR 3.50; p = 0.0001), and 58% (HR 2.51; p = 0.01), respectively. Isolated del(17p) and 1q21 + also conferred inferior PFS. The 4-year PFS was 65% for patients with one HRCA (HR 2.31; p = 0.0004) and 55% for those with ≥ 2 HRCAs (HR 2.75; p = 0.0001). In this large MRD-negative post-ASCT cohort, several HRCAs, including isolated HRCAs, remained clinically meaningful drivers of inferior PFS, highlighting that early MRD negativity does not uniformly mitigate the impact of high-risk biology.
The North American Prodromal Synucleinopathy study: protocol for a multi-site, longitudinal, observational study of idiopathic/isolated rapid eye movement sleep behavior disorder
Abstract Isolated/idiopathic rapid eye movement sleep behavior disorder (iRBD) is a usually prodromal manifestation of neurodegenerative disorders with α-synuclein pathology: Parkinson’s disease (PD), dementia with Lewy bodies (DLB), and multiple system atrophy (MSA). Clinical trials in the iRBD population face substantial barriers: limited access to well-characterized cohorts, inconsistent assessment protocols across centers, and the absence of validated biomarkers of disease burden. The North American Prodromal Synucleinopathy (NAPS) Consortium was established to address these challenges and facilitate clinical trials for neuroprotective therapies targeting synucleinopathy at the earliest known stages. In this multi-site, longitudinal, observational study, nine academic centers across North America will enroll and follow over 500 individuals with iRBD from existing sleep centers. Sixty control participants, matched for age, sex, and race will also be recruited. A harmonized protocol—including a standardized clinical battery assessing motor, cognitive, autonomic, psychiatric, sensory, and sleep function; structured diagnostic adjudication; biospecimen collection; and centralized analysis of both polysomnography and neuroimaging data—is outlined herein and reflects NAPS Stage 2. Each participants completes these assessments annually, and are replaced in the event of phenoconversion. By unifying assessments and expanding geographic reach, NAPS lays the groundwork for efficient, well-powered clinical trials designed to delay or prevent progression of iRBD to overt PD, DLB, or MSA—ultimately enabling earlier, more effective therapeutic intervention for neurodegenerative disease. Registered at clinicaltrials.gov (NCT05826457).
Network Hypoactivity in ALG13-CDG: Disrupted Developmental Pathways and E/I Imbalance as Early Drivers of Neurological Features in CDG
Background: ALG13-CDG is an X-linked N-linked glycosylation disorder caused by pathogenic variants in the glycosyltransferase ALG13, leading to severe neurological manifestations. Despite the clear CNS involvement, the impact of ALG13 dysfunction on human brain glycosylation and neurodevelopment remains unknown. We hypothesize that ALG13-CDG causes brain-specific hypoglycosylation that disrupts neurodevelopmental pathways and contributes directly to cortical network dysfunction. Methods: We generated iPSC-derived human cortical organoids (hCOs) from individuals with ALG13-CDG to define the impact of hypoglycosylation on cortical development and function. Electrophysiological activity was assessed using MEA recordings and integrated with multiomic profiling, including scRNA-seq, proteomics, glycoproteomics, N-glycan imaging, lipidomics, and metabolomics. X-inactivation status was evaluated in both iPSCs and hCOs. Results: ALG13-CDG hCOs showed reduced glycosylation of proteins involved in ECM organization, neuronal migration, lipid metabolism, calcium homeostasis, and neuronal excitability. These pathway disruptions were supported by proteomic and scRNA-seq data and included altered intercellular communication. Trajectory analyses revealed mistimed neuronal maturation with early inhibitory and delayed excitatory development, indicating an E/I imbalance. MEA recordings demonstrated early network hypoactivity with reduced firing rates, immature burst structure, and shortened axonal projections, while transcriptomic and proteomic signatures suggested emerging hyperexcitability. Altered lipid and GlcNAc metabolism, along with skewed X-inactivation, were also observed. Conclusions: Our study reveals that ALG13-CDG is a disorder of brain-specific hypoglycosylation that disrupts key neurodevelopmental pathways and destabilizes cortical network function. Through integrated multiomic and functional analyses, we identify early network hypoactivity, mistimed neuronal maturation, and evolving E/I imbalance that progresses to compensatory hyperexcitability, providing a mechanistic basis for seizure vulnerability. These findings redefine ALG13-CDG as disorders of cortical network instability, offering a new framework for targeted therapeutic intervention.
Clinically Suspected Neurodegeneration in Histiocytic Neoplasms as Causes of Neurologic Decline
Abstract Background The tau PET imaging with 18F‐flortacipir (18F‐FTP) has focused interest in accurately tracking longitudinal tau changes in Alzheimer's disease [1]. Thus, minimizing variability is critical. Off‐target signal has the potential to complicate interpretation of tau‐PET imaging due to potential spillover or bleed‐in effects, with increased effects seen in later stages of Alzheimer's due to cerebral atrophy and proximity of off‐target areas to relevant cortical areas[2]. Previously, we demonstrated the effect of uptake period activity on 18F‐FTP signal. With increasing recent interest in demographic factors that may affect off‐target binding, we investigated the effect of age in extra‐cerebral off‐target signal in 18F‐FTP PET imaging. Method Standard 18F‐FTP PET protocol was performed in 330 participants. Two independent readers measured tau uptake in predetermined off‐target regions, including extraocular muscle, meninges, and occipital bone among others. Linear regression models assessed the relationship between participants’ age, sex, and tau uptake values (SUV and SUVr) (SUV = (Tissue radioactivity concentration / Injected dose) / Body weight & SUVr = SUV of target region/ SUV of reference region.) Result Sex had a significant effect on off‐target signal in most brain regions, with variable positive or negative correlation based on area. Notably, SUV in the eyeball‐retina, occipital bone, upper skull meninges all showed significant positive correlation with sex, with ‘male’ status generally associated with lower SUV. The greatest effect of sex was observed in superior skull meninges, occipital bone, and internal carotid artery ( p <0.001). Age showed minimally affected SUV and SUVr in off‐target regions. SUVr values show a significant correlation with SUV values of upper skull meninges in sex. Cognitive status did not significantly affect off‐target SUV. Conclusion We observed that sex significantly affected extra‐brain off‐target signal in 18F‐FTP PET imaging, while age has minimal effect, adding to previous evidence of off‐target binding within brain regions. Further evaluation is necessary to understand the age‐related effects on off‐target regions. As a result, the variability introduced by sex may pose challenges to studying tau accumulation.
The Binding Patterns of Neurofibrillary Tangles Observed With High‐Resolution Autoradiography of
18
F MK 6240 and
18
F AV1451 Are Comparable and Predomina
Abstract Background An intense search is underway for tau PET tracers with enhanced capability to visualize tau aggregates. Research indicates that [18F] AV1451 and [18F]MK 6240 exhibit comparable binding properties in terms of spatial distribution and severity of tau aggregates, as observed both in‐vivo and in‐vitro. This study focused on head‐to‐head pathological comparison of both the tracers binding specificity to tangle maturity levels (pretangles, mature tangles and ghost tangles) of tau aggregates as seen on autoradiography as compared to CP‐13 (early tangle maturity marker) and PHF‐1(middling tangle maturity marker) immunohistochemical (IHC) stains in Alzheimer's disease (AD) and non‐AD tauopathies. Method Study participants included included those with AD and non‐AD tauopathies. Analyses were performed on serial 5um formalin fixed paraffin embedded postmortem human brain sections acquired from Mayo clinic brain bank. Visual assessment of colocalization with IHC as well as quantitative analyses were used. IHC sections were incubated with antibodies CP‐13 (recognizing early tangle maturity) and PHF‐1 (recognizing middling tangle maturity). Result A total of 38 participants were examined. The participants included a spectrum from normal to AD, including mild cognitive impairment (MCI) and atypical AD. Participants with N279K (4R), P301L (4R), and R406W MAPT mutations (3R+4R) were included as well. Both the tracers showed strong binding to AD tau aggregates and no or minimal binding to non‐AD tauopathies. Generally, early tangle maturity tau accumulation participants had more tau demonstrated with CP‐13 than PHF‐1 and both the tracers [18F]MK 6240 and [18F]AV 1451 binding are well correlated with the PHF‐1 staining suggesting the preference for middling tangle level and minimal to early tangles. Conclusion The emergence and validation of these new tau PET tracers have opened new opportunities for the development of more accurate diagnostic and management tools for AD. In our study on post‐mortem sections, [ 18 F]MK‐6240 and [ 18 F]Flortaucipir showed similar binding profiles with preference to middling tangle maturity levels.
NODDI reveals white matter microstructural changes in isolated REM sleep behavior disorder
Abstract Background Isolated REM sleep behavior disorder (iRBD) is a parasomnia that reflects an evolving α‐synucleinopathy disorder, providing an opportunity to study early pathological changes. While diffusion tensor imaging (DTI) studies have shown white matter changes in iRBD, Neurite Orientation Dispersion and Density Imaging (NODDI) may offer better biological specificity in characterizing microstructural alterations through measures of Neurite Density Index (NDI), Orientation Dispersion Index (ODI), and Free Water Fraction (FWF). Method We included 77 participants with polysomnography‐confirmed iRBD from the North American Prodromal Synucleinopathy (NAPS) Consortium and 154 age‐ and sex‐matched cognitively unimpaired controls from the Mayo Clinic Study of Aging. White matter microstructure was evaluated using standardized multi‐shell diffusion on 3T MRI, quantifying DTI metrics (fractional anisotropy, FA; and mean diffusivity, MD) and NODDI parameters across bilateral white matter tracts defined by the JHU “Eve” WM atlas. Group differences were assessed using conditional logistic regression, with correlations to motor performance evaluated using the Purdue Pegboard and Alternating Finger Tapping tests. Result Compared to controls, iRBD participants demonstrated widespread and bidirectional white matter changes across major white matter pathways (see Figure 1 for glass brain visualizations). While predominantly showing decreases, FA exhibited some increases, particularly in the corticospinal tract. MD showed a largely opposite pattern with predominantly increased values across tracts. NODDI metrics revealed complex bidirectional patterns: ODI was broadly increased across multiple tracts with focal decreases, while NDI showed a pattern of predominantly decreased values alongside localized increases. FWF demonstrated a mixed pattern with predominant decreases across most tracts. In addition, both DTI and NODDI metrics showed extensive, moderate correlations with the Purdue Pegboard Test and Alternating Finger Tapping performance ( T = 2.0, p < 0.05, Figure 2). Conclusion Our study highlighted widespread and complex bidirectional white matter microstructural alterations in individuals with iRBD, demonstrating significant correlations with dexterity and motor performance even during the prodromal stage. These results suggest that extensive white matter abnormalities occur early in prodromal α‐synucleinopathies and highlight the value of advanced diffusion imaging techniques in characterizing iRBD and its potential prediction of phenoconversion to overt neurodegenerative disorders.
Tau PET imaging in Black and Latino participants with and without cognitive impairment
Abstract Background Tau‐PET neuroimaging is increasingly applied to diagnose and stage, track progression, and assess response to putative disease‐modifying treatments in individuals with Alzheimer disease. However, it remains to be seen whether findings established in predominantly non‐Hispanic White (nHW) cohorts will generalize to Black and Latino participants who are underrepresented in dementia research. Method Community‐dwelling Black ( n = 83) and Latino participants ( n = 27) completed MRI (with quantification of white matter hyperintensity volumes), and amyloid‐ (PiB or florbetapir) and tau‐ (flortaucipir) PET brain imaging as part of a longitudinal study of memory and aging at Mayo Clinic in Florida. Global and regional tau‐PET standardized uptake value ratios (normalized to the cerebellar crus) were determined in Black and Latino participants and compared with findings from an independent cohort of nHW participants ( n = 110), 1:1‐matched for age, sex, education, and global Clinical Dementia Rating®. Conditional logistic modeling compared 47 regions of interest, adjusted for false discovery rate. Relevant associations between flortaucipir retention and clinical outcomes were assessed using Spearman rank correlations. Result Eighty‐three Black (mean 72±10.8‐years‐old, 63% female, 33% cognitively impaired) and 27 Latino participants (mean 65.8‐years‐old, 56% female, 11% cognitively impaired) completed neuroimaging. Data were compared with findings in 110 matched nHW individuals. Global tau‐PET burden was similar between matched cohorts (Black and nHW participants, mean SUVR: 1.34±0.39 vs 1.36±0.37, p = 0.71; Latino and nHW participants, mean SUVR: 1.17±0.09 vs 1.20±0.11, p = 0.66). Lower flortaucipir uptake was noted in the caudate ( p = 0.005) and putamen ( p = 0.022) of Black/Latino participants (vs nHW), although differences attenuated following adjustment for white matter hyperintensity volume. Global flortaucipir retention increased with age (Black: Rho=0.31; Latino: Rho=0.46; nHW: Rho=0.27; p <0.05), amyloid Centiloids (Black: Rho=0.65; Latino: Rho=0.41; nHW: Rho=0.58; p <0.05), and cognitive impairment (i.e., Clinical Dementia Rating® Sum‐of‐Box scores, Black/Latino: Rho=0.31, p = 0.07; nHW: 0.76, p <0.001). Conclusion Tau‐PET patterns were similar across ethnoracial groups after adjusting for white matter hyperintensity volumes—a biomarker of small vessel disease. Flortaucipir retention increased with age, amyloid accumulation, and cognitive impairment across all cohorts. These findings affirm the clinical and research applications of tau PET in diverse cohorts. Acknowledgements : Flortaucipir precursor and technology was supported by Avid Radiopharmaceuticals.