Challenging Neuromuscular Disease Cases.

The diagnosis of neuromuscular disorders requires a thorough history including family history and examination, with the next steps broadened now beyond electromyography and neuropathology to include genetic testing. The challenge in diagnosis can often be putting all the information together. With advances in genetic testing, some diagnoses that adult patients may have received as children deserve a second look and may result in diagnoses better defined or alternative diagnoses made. Clearly defining or redefining a diagnosis can result in understanding of potential other systems involved, prognosis, or potential treatments. This article presents several cases and approach to diagnosis as well as potential treatment and prognostic concerns, including seipinopathy, congenital myasthenic syndrome, central core myopathy, and myotonic dystrophy type 2.

A Review of Clinical and Imaging Findings in Tumefactive Demyelination.

OBJECTIVE. Tumefactive demyelination mimics primary brain neoplasms on imaging, often necessitating brain biopsy. This article reviews the literature for the clinical and radiologic findings of tumefactive demyelination in various disease processes to facilitate identification of tumefactive demyelination on imaging. CONCLUSION. Both clinical and radiologic findings must be integrated to distinguish tumefactive demyelinating lesions from similarly appearing lesions on imaging. Further research on the immunopathogenesis of tumefactive demyelination and associated conditions will elucidate their interrelationship.

Interpretable multimodal deep learning for real-time pan-tissue pan-disease pathology search on social media.

Pathologists are responsible for rapidly providing a diagnosis on critical health issues. Challenging cases benefit from additional opinions of pathologist colleagues. In addition to on-site colleagues, there is an active worldwide community of pathologists on social media for complementary opinions. Such access to pathologists worldwide has the capacity to improve diagnostic accuracy and generate broader consensus on next steps in patient care. From Twitter we curate 13,626 images from 6,351 tweets from 25 pathologists from 13 countries. We supplement the Twitter data with 113,161 images from 1,074,484 PubMed articles. We develop machine learning and deep learning models to (i) accurately identify histopathology stains, (ii) discriminate between tissues, and (iii) differentiate disease states. Area Under Receiver Operating Characteristic (AUROC) is 0.805-0.996 for these tasks. We repurpose the disease classifier to search for similar disease states given an image and clinical covariates. We report precision@k = 1 = 0.7618 ± 0.0018 (chance 0.397 ± 0.004, mean ±stdev ). The classifiers find that texture and tissue are important clinico-visual features of disease. Deep features trained only on natural images (e.g., cats and dogs) substantially improved search performance, while pathology-specific deep features and cell nuclei features further improved search to a lesser extent. We implement a social media bot (@pathobot on Twitter) to use the trained classifiers to aid pathologists in obtaining real-time feedback on challenging cases. If a social media post containing pathology text and images mentions the bot, the bot generates quantitative predictions of disease state (normal/artifact/infection/injury/nontumor, preneoplastic/benign/low-grade-malignant-potential, or malignant) and lists similar cases across social media and PubMed. Our project has become a globally distributed expert system that facilitates pathological diagnosis and brings expertise to underserved regions or hospitals with less expertise in a particular disease. This is the first pan-tissue pan-disease (i.e., from infection to malignancy) method for prediction and search on social media, and the first pathology study prospectively tested in public on social media. We will share data through http://pathobotology.org . We expect our project to cultivate a more connected world of physicians and improve patient care worldwide.

Postnatal hypoxia evokes persistent changes within the male rat's dopaminergic system.

PURPOSE: Hypoxic insults occurring during the perinatal period remain the leading cause of permanent brain impairment. Severe cognitive and motor dysfunction, as seen in cerebral palsy, will occur in 4-10% of post-hypoxic newborns. Subtle cognitive impairment, apparent in disorders of minimal brain dysfunction will occur in > 3 million post-hypoxic newborns. Analyses of post-hypoxic rodent brains reveal reduced extracellular levels of dopamine, a key neurotransmitter of vigilance, execute function, and behavior. The purpose of this study was to assess whether synaptic levels of dopamine could be enhanced in post-hypoxic, hypodopaminergic rats. METHODS: Newborn male rats were exposed to subtle, repetitive hypoxic insults for 4-6 h per day, during postnatal days 7-11. During adolescence, we quantified dopamine content within the caudate nuclei. We then determined whether extracellular dopamine levels could be increased by injecting the psychostimulant d-amphetamine. We next assessed whether the post-hypoxic rat's response to d-amphetamine would differentially impact place preference behavior when compared with littermate controls. RESULTS: Total tissue content of dopamine was significantly higher in post-hypoxic rats. Injection of d-amphetamine liberated that dopamine which subsequently enhanced extracellular levels. Post-hypoxic rats acquired conditioned place preference for d-amphetamine during the training days. During the testing day, total time spent in the amphetamine-pairing box did not differ between post-hypoxic and control littermates. CONCLUSION: Postnatally occurring hypoxic insults promote remodeling of the dopaminergic system resulting in increased intracellular sequestering of this monoamine. That sequestered dopamine can be released using the psychostimulant d-amphetamine, which did not promote a conditioned place preference any greater than was observed in non-hypoxic littermate controls.

Imaging correlates for the 2016 update on WHO classification of grade II/III gliomas: implications for IDH, 1p/19q and ATRX status.

The 2016 World Health Organization Classification of Tumors of the Central Nervous System incorporates the use of molecular information into the classification of brain tumors, including grade II and III gliomas, providing new prognostic information that cannot be delineated based on histopathology alone. We hypothesized that these genomic subgroups may also have distinct imaging features. A retrospective single institution study was performed on 40 patients with pathologically proven infiltrating WHO grade II/III gliomas with a pre-treatment MRI and molecular data on IDH, chromosomes 1p/19q and ATRX status. Two blinded Neuroradiologists qualitatively assessed MR features. The relationship between each parameter and molecular subgroup (IDH-wildtype; IDH-mutant-1p/19q codeleted-ATRX intact; IDH-mutant-1p/19q intact-ATRX loss) was evaluated with Fisher's exact test. Progression free survival (PFS) was also analyzed. A border that could not be defined on FLAIR was most characteristic of IDH-wildtype tumors, whereas IDH-mutant tumors demonstrated either well-defined or slightly ill-defined borders (p = 0.019). Degree of contrast enhancement and presence of restricted diffusion did not distinguish molecular subgroups. Frontal lobe predominance was associated with IDH-mutant tumors (p = 0.006). The IDH-wildtype subgroup had significantly shorter PFS than the IDH-mutant groups (p < 0.001). No differences in PFS were present when separating by tumor grade. FLAIR border patterns and tumor location were associated with distinct molecular subgroups of grade II/III gliomas. These imaging features may provide fundamental prognostic and predictive information at time of initial diagnostic imaging.

Erratum to: Imaging correlates for the 2016 update on WHO classification of grade II/III gliomas: implications for IDH, 1p/19q and ATRX status.

In the initial online publication, the values in the last two rows in Table 1 were in the wrong rows. The original article has been corrected.

Soluble Urokinase Receptor Is Released Selectively by Glioblastoma Cells That Express Epidermal Growth Factor Receptor Variant III and Promotes Tumor Cell Migration and Invasion.

Genomic heterogeneity is characteristic of glioblastoma (GBM). In many GBMs, the EGF receptor gene (EGFR) is amplified and may be truncated to generate a constitutively active form of the receptor called EGFRvIII. EGFR gene amplification and EGFRvIII are associated with GBM progression, even when only a small fraction of the tumor cells express EGFRvIII. In this study, we show that EGFRvIII-positive GBM cells express significantly increased levels of cellular urokinase receptor (uPAR) and release increased amounts of soluble uPAR (suPAR). When mice were xenografted with human EGFRvIII-expressing GBM cells, tumor-derived suPAR was detected in the plasma, and the level was significantly increased compared with that detected in plasma samples from control mice xenografted with EGFRvIII-negative GBM cells. suPAR also was increased in plasma from patients with EGFRvIII-positive GBMs. Purified suPAR was biologically active when added to cultures of EGFRvIII-negative GBM cells, activating cell signaling and promoting cell migration and invasion. suPAR did not significantly stimulate cell signaling or migration of EGFRvIII-positive cells, probably because cell signaling was already substantially activated in these cells. The activities of suPAR were replicated by conditioned medium (CM) from EGFRvIII-positive GBM cells. When the CM was preincubated with uPAR-neutralizing antibody or when uPAR gene expression was silenced in cells used to prepare CM, the activity of the CM was significantly attenuated. These results suggest that suPAR may function as an important paracrine signaling factor in EGFRvIII-positive GBMs, inducing an aggressive phenotype in tumor cells that are EGFRvIII-negative.

Effects of gene replacement therapy with resamirigene bilparvovec (AT132) on skeletal muscle pathology in X-linked myotubular myopathy: results from a substudy of the ASPIRO open-label clinical trial.

BACKGROUND: X-linked myotubular myopathy (XLMTM) is a rare, life-threatening congenital muscle disease caused by mutations in the MTM1 gene that result in profound muscle weakness, significant respiratory insufficiency, and high infant mortality. There is no approved disease-modifying therapy for XLMTM. Resamirigene bilparvovec (AT132; rAAV8-Des-hMTM1) is an investigational adeno-associated virus (AAV8)-mediated gene replacement therapy designed to deliver MTM1 to skeletal muscle cells and achieve long-term correction of XLMTM-related muscle pathology. The clinical trial ASPIRO (NCT03199469) investigating resamirigene bilparvovec in XLMTM is currently paused while the risk:benefit balance associated with this gene therapy is further investigated. METHODS: Muscle biopsies were taken before treatment and 24 and 48 weeks after treatment from ten boys with XLMTM in a clinical trial of resamirigene bilparvovec (ASPIRO; NCT03199469). Comprehensive histopathological analysis was performed. FINDINGS: Baseline biopsies uniformly showed findings characteristic of XLMTM, including small myofibres, increased internal or central nucleation, and central aggregates of organelles. Biopsies taken at 24 weeks post-treatment showed marked improvement of organelle localisation, without apparent increases in myofibre size in most participants. Biopsies taken at 48 weeks, however, did show statistically significant increases in myofibre size in all nine biopsies evaluated at this timepoint. Histopathological endpoints that did not demonstrate statistically significant changes with treatment included the degree of internal/central nucleation, numbers of triad structures, fibre type distributions, and numbers of satellite cells. Limited (predominantly mild) treatment-associated inflammatory changes were seen in biopsy specimens from five participants. INTERPRETATION: Muscle biopsies from individuals with XLMTM treated with resamirigene bilparvovec display statistically significant improvement in organelle localisation and myofibre size during a period of substantial improvements in muscle strength and respiratory function. This study identifies valuable histological endpoints for tracking treatment-related gains with resamirigene bilparvovec, as well as endpoints that did not show strong correlation with clinical improvement in this human study. FUNDING: Astellas Gene Therapies (formerly Audentes Therapeutics, Inc.).

Magnetic Resonance Imaging of Iron Metabolism with T2* Mapping Predicts an Enhanced Clinical Response to Pharmacologic Ascorbate in Patients with GBM.

PURPOSE: Pharmacologic ascorbate (P-AscH-) is hypothesized to be an iron (Fe)-dependent tumor-specific adjuvant to chemoradiation in treating glioblastoma (GBM). This study determined the efficacy of combining P-AscH- with radiation and temozolomide in a phase II clinical trial while simultaneously investigating a mechanism-based, noninvasive biomarker in T2* mapping to predict GBM response to P-AscH- in humans. PATIENTS AND METHODS: The single-arm phase II clinical trial (NCT02344355) enrolled 55 subjects, with analysis performed 12 months following the completion of treatment. Overall survival (OS) and progression-free survival (PFS) were estimated with the Kaplan-Meier method and compared across patient subgroups with log-rank tests. Forty-nine of 55 subjects were evaluated using T2*-based MRI to assess its utility as an Fe-dependent biomarker. RESULTS: Median OS was estimated to be 19.6 months [90% confidence interval (CI), 15.7-26.5 months], a statistically significant increase compared with historic control patients (14.6 months). Subjects with initial T2* relaxation < 50 ms were associated with a significant increase in PFS compared with T2*-high subjects (11.2 months vs. 5.7 months, P < 0.05) and a trend toward increased OS (26.5 months vs. 17.5 months). These results were validated in preclinical in vitro and in vivo model systems. CONCLUSIONS: P-AscH- combined with temozolomide and radiotherapy has the potential to significantly enhance GBM survival. T2*-based MRI assessment of tumor iron content is a prognostic biomarker for GBM clinical outcomes. See related commentary by Nabavizadeh and Bagley, p. 255.

Ventriculus terminalis cyst in an infant: a case report.

BACKGROUND: Filar cysts are frequently found on neonatal ultrasound and are physiologically involuting structures with natural resolution. Hence, there has been no previous histologic correlation. Ventriculus terminalis is a focal central canal dilation in the conus medullaris and usually not clinically significant. Extra-axial cyst at the conus-filum junction connected to ventriculus terminalis is extremely rare, especially when associated with tethered lipomatous filum terminale and with progressive cyst enlargement. CASE PRESENTATION: A Caucasian female neonate with abnormal gluteal cleft had ventriculus terminalis cyst with an extra-axial cyst at the conus-filar junction and taut lipomatous filum on ultrasound examination and magnetic resonance imaging. This persisted at 6-month follow up imaging. In light of the nonresolving extra-axial mass and thick taut lipomatous filum, the child underwent L1-L3 osteoplastic laminectomies. The extra-axial cyst expanded after bony decompression and furthermore on dural opening; visualized on ultrasound. It communicated with the central canal and was documented with intraoperative photomicrographs. It was excised and filum sectioned. Histological immunostaining of the cyst wall showed neuroglial and axonal elements. The child did well without deficits at 4-year follow up with normal urodynamics. CONCLUSION: Progression dilation of ventriculus terminalis and extra-axial conofilar cyst with tethered lipomatous filum will likely progress to clinical significance and require surgical intervention. The embryologic basis for this pathology is discussed, with literature review.

The inflammatory pathology of dysferlinopathy is distinct from calpainopathy, Becker muscular dystrophy, and inflammatory myopathies.

The descriptions of muscle pathology in dysferlinopathy patients have classically included an inflammatory infiltrate that can mimic inflammatory myopathies. Based on over 20 years of institutional experience in evaluating dystrophic and inflammatory myopathy muscle biopsies at the University of Iowa, we hypothesized the inflammatory histopathology of dysferlinopathy is more similar to limb-girdle pattern muscular dystrophies such as calpainopathy and Becker muscular dystrophy, and distinct from true inflammatory myopathies. Muscle biopsies from 32 dysferlinopathy, 30 calpainopathy, 30 Becker muscular dystrophy, and 30 inflammatory myopathies (15 each of dermatomyositis and inclusion body myositis) were analyzed through digital quantitation of CD3, CD4, CD8, CD20, and PU.1 immunostaining. The expression of MHC class I and deposition of complement C5b-9 was also evaluated. Dysferlinopathy, calpainopathy, and Becker muscular dystrophy muscle biopsies had similar numbers of inflammatory cell infiltrates and significantly fewer CD3+ T-lymphocytes than dermatomyositis (p = 0.05) and inclusion body myositis (p < 0.0001) biopsies. There was no statistically significant difference in the number of PU.1+ macrophages identified in any diagnostic group. MHC class I expression was significantly lower in the limb-girdle pattern muscular dystrophies compared to the inflammatory myopathies (p < 0.0001). In contrast, complement C5b-9 deposition was similar among dysferlinopathy, dermatomyositis, and inclusion body myositis biopsies but significantly greater than calpainopathy and Becker muscular dystrophy biopsies (p = 0.05). Compared to calpainopathy, Becker muscular dystrophy, and inflammatory myopathies, the unique profile of minimal inflammatory cell infiltrates, absent to focal MHC class I, and diffuse myofiber complement C5b-9 deposition is the pathologic signature of dysferlinopathy muscle biopsies.

Deep Neural Network Analysis of Pathology Images With Integrated Molecular Data for Enhanced Glioma Classification and Grading.

Gliomas are primary brain tumors that originate from glial cells. Classification and grading of these tumors is critical to prognosis and treatment planning. The current criteria for glioma classification in central nervous system (CNS) was introduced by World Health Organization (WHO) in 2016. This criteria for glioma classification requires the integration of histology with genomics. In 2017, the Consortium to Inform Molecular and Practical Approaches to CNS Tumor Taxonomy (cIMPACT-NOW) was established to provide up-to-date recommendations for CNS tumor classification, which in turn the WHO is expected to adopt in its upcoming edition. In this work, we propose a novel glioma analytical method that, for the first time in the literature, integrates a cellularity feature derived from the digital analysis of brain histopathology images integrated with molecular features following the latest WHO criteria. We first propose a novel over-segmentation strategy for region-of-interest (ROI) selection in large histopathology whole slide images (WSIs). A Deep Neural Network (DNN)-based classification method then fuses molecular features with cellularity features to improve tumor classification performance. We evaluate the proposed method with 549 patient cases from The Cancer Genome Atlas (TCGA) dataset for evaluation. The cross validated classification accuracies are 93.81% for lower-grade glioma (LGG) and high-grade glioma (HGG) using a regular DNN, and 73.95% for LGG II and LGG III using a residual neural network (ResNet) DNN, respectively. Our experiments suggest that the type of deep learning has a significant impact on tumor subtype discrimination between LGG II vs. LGG III. These results outperform state-of-the-art methods in classifying LGG II vs. LGG III and offer competitive performance in distinguishing LGG vs. HGG in the literature. In addition, we also investigate molecular subtype classification using pathology images and cellularity information. Finally, for the first time in literature this work shows promise for cellularity quantification to predict brain tumor grading for LGGs with IDH mutations.

Catalase Overexpression Drives an Aggressive Phenotype in Glioblastoma.

Glioblastoma remains the deadliest form of brain cancer, largely because these tumors become resistant to standard of care treatment with radiation and chemotherapy. Intracellular production of reactive oxygen species (ROS) is necessary for chemo- and radiotherapy-induced cytotoxicity. Here, we assessed whether antioxidant catalase (CAT) affects glioma cell sensitivity to temozolomide and radiation. Using The Cancer Genome Atlas database, we found that CAT mRNA expression is upregulated in glioma tumor tissue compared with non-tumor tissue, and the level of expression negatively correlates with the overall survival of patients with high-grade glioma. In U251 glioma cells, CAT overexpression substantially decreased the basal level of hydrogen peroxide, enhanced anchorage-independent cell growth, and facilitated resistance to the chemotherapeutic drug temozolomide and ionizing radiation. Importantly, pharmacological inhibition of CAT activity reduced the proliferation of glioma cells isolated from patient biopsy samples. Moreover, U251 cells overexpressing CAT formed neurospheres in neurobasal medium, whereas control cells did not, suggesting that the radio- and chemoresistance conferred by CAT may be due in part to the enrichment of glioma stem cell populations. Finally, CAT overexpression significantly decreased survival in an orthotopic mouse model of glioma. These results demonstrate that CAT regulates chemo- and radioresistance in human glioma.

Vascular Involvement in Neurosarcoidosis: Early Experiences From Intracranial Vessel Wall Imaging.

BACKGROUND AND OBJECTIVES: Cerebrovascular manifestations in neurosarcoidosis (NS) were previously considered rare but are being increasingly recognized. We report our preliminary experience in patients with NS who underwent high-resolution vessel wall imaging (VWI). METHODS: A total of 13 consecutive patients with NS underwent VWI. Images were analyzed by 2 neuroradiologists in consensus. The assessment included segment-wise evaluation of larger- and medium-sized vessels (internal carotid artery, M1-M3 middle cerebral artery; A1-A3 anterior cerebral artery; V4 segments of vertebral arteries; basilar artery; and P1-P3 posterior cerebral artery), lenticulostriate perforator vessels, and medullary and deep cerebral veins. Cortical veins were not assessed due to flow-related artifacts. Brain biopsy findings were available in 6 cases and were also reviewed. RESULTS: Mean patient age was 54.9 years (33-71 years) with an M:F of 8:5. Mean duration between initial diagnosis and VWI study was 18 months. Overall, 9/13 (69%) patients had vascular abnormalities. Circumferential large vessel enhancement was seen in 3/13 (23%) patients, whereas perforator vessel involvement was seen in 6/13 (46%) patients. Medullary and deep vein involvement was also seen in 6/13 patients. In addition, 7/13 (54%) patients had microhemorrhages in susceptibility-weighted imaging, and 4/13 (31%) had chronic infarcts. On biopsy, 5/6 cases showed perivascular granulomas with vessel wall involvement in all 5 cases. DISCUSSION: Our preliminary findings suggest that involvement of intracranial vascular structures may be a common finding in patients with NS and should be routinely looked for. These findings appear concordant with previously reported autopsy literature and need to be validated on a larger scale.

Teaching Pathology in an Integrated Preclinical Medical School Curriculum and Adaptations to COVID-19 Restrictions.

The coronavirus disease 2019 (COVID-19) pandemic has had a major impact on education at all age levels, including professional schools and health professions programs. We describe the experience of adapting preclinical medical school courses within an integrated curriculum to virtual instruction. A major feature of two of the courses were pathology small groups adapted from pathology courses in the previous medical school curriculum. These small groups were designed to use facilitated groups of 8 to 10 students. With a sudden change to virtual learning, these small groups were shifted to large group virtual sessions. In general, the conversion went well, with ongoing optimization of the format of the large group sessions mainly occurring over the first several sessions. End-of-course student evaluations were generally positive, but with a preference toward returning to live sessions in the future. Scores on 5 multiple choice examinations in the spring 2020 course were essentially identical in mean, standard deviation, and distribution to examinations in the previous 2 years of the course that had similar layout and topic organization. We discuss the challenges and successes of the switch to virtual instruction and of teaching pathology content within an integrated medical school curriculum.

Liver metastases from pituitary carcinomas mimicking visceral well-differentiated neuroendocrine tumors: a series of four cases.

BACKGROUND: Pathologists frequently encounter neuroendocrine tumors (NETs) presenting as multiple liver masses in routine practice. Most often, these are well-differentiated tumors with characteristic histologic features. In contrast, pituitary carcinoma is very rare, and there is limited data on its natural history and pathologic characterization. METHODS: The aim of this study was to describe clinical characteristics, histomorphology, immunophenotype and follow-up of pituitary carcinoma involving the liver and mimicking well-differentiated NETs of visceral origin. We selected a group of well-differentiated NETs of the pancreas to use as immunophenotypic controls. We identified 4 patients (age range, 51 to 73) with pituitary corticotroph carcinoma with liver metastases. Three patients presented with Cushing syndrome. RESULTS: All cases histologically resembled well-differentiated NETs of visceral origin with Ki-67 proliferation indices of 5-42% and expression of T-PIT; metastatic tumors were not immunoreactive with CDX2, Islet 1 or TTF-1. CONCLUSIONS: Frequently, these cases display adrenocorticotropic hormone (ACTH) secretion and pituitary-specific transcription factor immunohistochemistry may be used as a reliable marker to distinguish metastatic pituitary carcinoma from NETs of visceral origin in addition to delineating a corticotroph carcinoma from somatotroph, lactotroph, thyrotroph, and gonadotroph lineage. Although rare, the differential diagnosis of pituitary carcinoma should be considered in metastatic well-differentiated NETs in which the site of origin is uncertain. In summary, pituitary corticotroph carcinoma can metastasize to the liver and mimic well-differentiated NET.

Survival after reoperation for recurrent glioblastoma.

Determining which patients will benefit from reoperation for recurrent glioblastoma remains difficult and the impact of the volume of FLAIR signal hyperintensity is not well known. The primary purpose of this study is to analyze the impact of preoperative volume of FLAIR hyperintensity on prognosis. 37 patients who underwent a reoperation for recurrent glioblastoma after initial gross total resection followed by standard chemoradiation were retrospectively reviewed. Volumetric analysis of preoperative MR images from the initial and second surgery was performed and correlated with clinical data. Survival probabilities were estimated using the Kaplan-Meier method and Cox regression to assess the effect of risk factors on time to reoperation (TTR), progression-free survival (PFS) after reoperation, and overall survival (OS). The volumes of FLAIR signal hyperintensity prior to the initial surgery and reoperation were not associated with prognosis. TTR and OS were significantly affected by the preoperative enhancement volume at the initial surgery, with increasing volumes yielding poorer prognosis. Patients with tumor in critical/eloquent areas were found to have a worse prognosis. Median TTR was 11 months, median PFS after reoperation was 3 months, and OS in patients undergoing a reoperation was 21 months. The results suggest FLAIR signal change seen in patients with glioblastoma does not influence time to reoperation, progression-free survival, or overall survival. These findings suggest the amount of FLAIR signal change should not greatly influence a surgeon's decision to perform a second surgical resection compare to other factors, and when appropriate, aggressive surgical intervention should be considered.

BCR-NTRK2 fusion in a low-grade glioma with distinctive morphology and unexpected aggressive behavior.

A 52-yr-old man was found to have a 6.6-cm left frontotemporal mass. Biopsy revealed a low-grade astrocytic neoplasm with significant infiltration and an unusual morphologic appearance. Only rare mitotic figures were seen and the Ki-67 proliferative index was very low. Unexpectedly, the low-grade astrocytoma showed rapid progression within a short time, but subsequent resection showed similar histologic findings to the original biopsy with only slightly more mitoses and a marginally increased Ki-67 proliferative index. Molecular testing performed on the tumor showed no alterations in the IDH1, IDH2, EGFR, or BRAF genes by sequencing, intact 1p/19q by FISH, and a novel BCR-NTRK2 fusion transcript by reverse transcription and anchored multiplex PCR. The patient underwent standard-of-care therapy, both first and second line, for a high-grade glioma because of the aggressive behavior, but the glioma continued to progress despite treatment, and the patient died within 13.5 mo of the original diagnosis. At the time of diagnosis, the BCR-NTRK2 fusion transcript had not been described in solid tumors; however, a recent publication described this fusion transcript in two glioblastomas. Although no approved therapy was available for this patient, FDA approval has now been given for solid tumors with any NTRK gene family fusions. This unexpected molecular finding in a deceptively low-grade-appearing glioma supports the use of expanded molecular testing in gliomas and solid tumors, particularly in instances where targeted therapies are available.

Glioma grading using structural magnetic resonance imaging and molecular data.

A glioma grading method using conventional structural magnetic resonance image (MRI) and molecular data from patients is proposed. The noninvasive grading of glioma tumors is obtained using multiple radiomic texture features including dynamic texture analysis, multifractal detrended fluctuation analysis, and multiresolution fractal Brownian motion in structural MRI. The proposed method is evaluated using two multicenter MRI datasets: (1) the brain tumor segmentation (BRATS-2017) challenge for high-grade versus low-grade (LG) and (2) the cancer imaging archive (TCIA) repository for glioblastoma (GBM) versus LG glioma grading. The grading performance using MRI is compared with that of digital pathology (DP) images in the cancer genome atlas (TCGA) data repository. The results show that the mean area under the receiver operating characteristic curve (AUC) is 0.88 for the BRATS dataset. The classification of tumor grades using MRI and DP images in TCIA/TCGA yields mean AUC of 0.90 and 0.93, respectively. This work further proposes and compares tumor grading performance using molecular alterations (IDH1/2 mutations) along with MRI and DP data, following the most recent World Health Organization grading criteria, respectively. The overall grading performance demonstrates the efficacy of the proposed noninvasive glioma grading approach using structural MRI.

Clinical, genetic, and pathologic characterization of FKRP Mexican founder mutation c.1387A>G.

OBJECTIVE: To characterize the clinical phenotype, genetic origin, and muscle pathology of patients with the FKRP c.1387A>G mutation. METHODS: Standardized clinical data were collected for all patients known to the authors with c.1387A>G mutations in FKRP. Muscle biopsies were reviewed and used for histopathology, immunostaining, Western blotting, and DNA extraction. Genetic analysis was performed on extracted DNA. RESULTS: We report the clinical phenotypes of 6 patients homozygous for the c.1387A>G mutation in FKRP. Onset of symptoms was <2 years, and 5 of the 6 patients never learned to walk. Brain MRIs were normal. Cognition was normal to mildly impaired. Microarray analysis of 5 homozygous FKRP c.1387A>G patients revealed a 500-kb region of shared homozygosity at 19q13.32, including FKRP. All 4 muscle biopsies available for review showed end-stage dystrophic pathology, near absence of glycosylated α-dystroglycan (α-DG) by immunofluorescence, and reduced molecular weight of α-DG compared with controls and patients with homozygous FKRP c.826C>A limb-girdle muscular dystrophy. CONCLUSIONS: The clinical features and muscle pathology in these newly reported patients homozygous for FKRP c.1387A>G confirm that this mutation causes congenital muscular dystrophy. The clinical severity might be explained by the greater reduction in α-DG glycosylation compared with that seen with the c.826C>A mutation. The shared region of homozygosity at 19q13.32 indicates that FKRP c.1387A>G is a founder mutation with an estimated age of 60 generations (∼1,200-1,500 years).