Clinical utility of whole-genome DNA methylation profiling as a primary molecular diagnostic assay for central nervous system tumors-A prospective study and guidelines for clinical testing.

Background: Central nervous system (CNS) cancer is the 10th leading cause of cancer-associated deaths for adults, but the leading cause in pediatric patients and young adults. The variety and complexity of histologic subtypes can lead to diagnostic errors. DNA methylation is an epigenetic modification that provides a tumor type-specific signature that can be used for diagnosis. Methods: We performed a prospective study using DNA methylation analysis as a primary diagnostic method for 1921 brain tumors. All tumors received a pathology diagnosis and profiling by whole genome DNA methylation, followed by next-generation DNA and RNA sequencing. Results were stratified by concordance between DNA methylation and histopathology, establishing diagnostic utility. Results: Of the 1602 cases with a World Health Organization histologic diagnosis, DNA methylation identified a diagnostic mismatch in 225 cases (14%), 78 cases (5%) did not classify with any class, and in an additional 110 (7%) cases DNA methylation confirmed the diagnosis and provided prognostic information. Of 319 cases carrying 195 different descriptive histologic diagnoses, DNA methylation provided a definitive diagnosis in 273 (86%) cases, separated them into 55 methylation classes, and changed the grading in 58 (18%) cases. Conclusions: DNA methylation analysis is a robust method to diagnose primary CNS tumors, improving diagnostic accuracy, decreasing diagnostic errors and inconclusive diagnoses, and providing prognostic subclassification. This study provides a framework for inclusion of DNA methylation profiling as a primary molecular diagnostic test into professional guidelines for CNS tumors. The benefits include increased diagnostic accuracy, improved patient management, and refinements in clinical trial design.

Fatal central nervous system co-infection with SARS-CoV-2 and tuberculosis in a healthy child.

BACKGROUND: Central and peripheral nervous system symptoms and complications are being increasingly recognized among individuals with pandemic SARS-CoV-2 infections, but actual detection of the virus or its RNA in the central nervous system has rarely been sought or demonstrated. Severe or fatal illnesses are attributed to SARS-CoV-2, generally without attempting to evaluate for alternative causes or co-pathogens. CASE PRESENTATION: A five-year-old girl with fever and headache was diagnosed with acute SARS-CoV-2-associated meningoencephalitis based on the detection of its RNA on a nasopharyngeal swab, cerebrospinal fluid analysis, and magnetic resonance imaging findings. Serial serologic tests for SARS-CoV-2 IgG and IgA showed seroconversion, consistent with an acute infection. Mental status and brain imaging findings gradually worsened despite antiviral therapy and intravenous dexamethasone. Decompressive suboccipital craniectomy for brain herniation with cerebellar biopsy on day 30 of illness, shortly before death, revealed SARS-CoV-2 RNA in cerebellar tissue using the Centers for Disease Control and Prevention 2019-nCoV Real-Time Reverse Transcriptase-PCR Diagnostic Panel. On histopathology, necrotizing granulomas with numerous acid-fast bacilli were visualized, and Mycobacterium tuberculosis complex DNA was detected by PCR. Ventricular cerebrospinal fluid that day was negative for mycobacterial DNA. Tracheal aspirate samples for mycobacterial DNA and culture from days 22 and 27 of illness were negative by PCR but grew Mycobacterium tuberculosis after 8 weeks, long after the child's passing. She had no known exposures to tuberculosis and no chest radiographic findings to suggest it. All 6 family members had normal chest radiographs and negative interferon-γ release assay results. The source of her tuberculous infection was not identified, and further investigations by the local health department were not possible because of the State of Michigan-mandated lockdown for control of SARS-CoV-2 spread. CONCLUSION: The detection of SARS-CoV-2 RNA in cerebellar tissue and the demonstration of seroconversion in IgG and IgA assays was consistent with acute SARS-CoV-2 infection of the central nervous infection. However, the cause of death was brain herniation from her rapidly progressive central nervous system tuberculosis. SARS-CoV-2 may mask or worsen occult tuberculous infection with severe or fatal consequences.

A rare case of TLE1-positive sclerosing epithelioid fibrosarcoma expanding the differential diagnosis of TLE1-positive tumors: a case report.

Transducin-like enhancer of split 1 (TLE1) is a transcription factor known for its strong overexpression and immunopositivity in synovial sarcoma. Several studies have revealed that its immunopositivity is not always specific to synovial sarcoma, with several cases showing positivity in peripheral nerve sheath tumors and solitary fibrous tumors. Occasional weak staining for TLE1 has also been described in clear cell sarcoma, high-grade chondrosarcoma, Ewing sarcoma, rhabdomyosarcoma, GIST, myxofibrosarcoma, and leiomyosarcoma. Here we present the first unique case of sclerosing epithelioid fibrosarcoma with strong, diffuse TLE1 positivity, resulting in a new consideration for the differential diagnosis of TLE1 positivity.

Pitfalls in Diagnosis and Management of Testicular Choriocarcinoma Metastatic to the Brain: Report of 2 Cases and Review of Literature.

INTRODUCTION: Pure choriocarcinoma of the testes is a rare, aggressive germ cell tumor that can metastasize to the brain. Although its prognosis has improved with the development of cisplatin-based chemotherapy regimens, cerebral metastases are prone to hemorrhage and associated with high morbidity. Here, we present 2 cases of testicular choriocarcinoma with cerebral metastasis and discuss potential pitfalls in their diagnosis and management. We also review cases in the literature that feature these rare lesions. METHODS: Medline was searched for all publications including the terms "testicular choriocarcinoma" and "cerebral metastasis" or "brain metastasis." Articles that included patients with tumors classified as a mix of choriocarcinoma and other germ cell tumor subtypes were excluded. RESULTS: A total of 15 cases from the literature and our own 2 cases were included in the analysis. The mean age at presentation was 25.5 years. Neurologic symptoms accounted for the initial presentation of 9 patients (60%). Outcomes were predominantly poor, with 10 patients (67%) expiring shortly after their initial diagnosis. Three of these deaths were related to mass effect from metastasis-related hemorrhages. Two patients underwent emergent decompressive craniectomies, and both died from cerebral herniation. CONCLUSION: The potentially catastrophic nature of choriocarcinoma-related cerebral hemorrhages underscores the need for prompt, accurate diagnosis and aggressive surgical management of these lesions. Their highly vascular nature and lack of findings on cerebral angiography may cause them to be confused with occult vascular malformations.

Aberrant detergent-insoluble excitatory amino acid transporter 2 accumulates in Alzheimer disease.

Alzheimer disease (AD) is characterized by deposition of amyloid-beta, tau, and other specific proteins that accumulate in the brain in detergent-insoluble complexes. Alzheimer disease also involves glutamatergic neurotransmitter system disturbances. Excitatory amino acid transporter 2 (EAAT2) is the dominant glutamate transporter in cerebral cortex and hippocampus. We investigated whether accumulation of detergent-insoluble EAAT2 is related to cognitive impairment and neuropathologic changes in AD by quantifying detergent-insoluble EAAT2 levels in hippocampus and frontal cortex of cognitively normal patients, patients with clinical dementia rating of 0.5 (mildly impaired), and AD patients. Parkinson disease patients served as neurodegenerative disease controls. We found that Triton X-100-insoluble EAAT2 levels were significantly increased in patients with AD compared with controls, whereas Triton X-100-insoluble EAAT2 levels inpatients with clinical dementia rating of 0.5 were intermediately elevated between control and AD subjects. Detergent insolubility of presenilin-1, a structurally similar protein, did not differ among the groups, thus arguing that EAAT2 detergent insolubility was not caused by nonspecific cellular injury. These findings demonstrate that detergent-insoluble EAAT2 accumulation is a progressive biochemical lesion that correlates with cognitive impairment and neuropathologic changes in AD. These findings lend further support to the idea that dysregulation of the glutamatergic system may play a significant role in AD pathogenesis.

Enzymes that synthesize the IB4 epitope are not sufficient to impart IB4 binding in dorsal root ganglia of rat.

The isolectin B4 (IB4) stains a subset of small and medium-sized dorsal root ganglion (DRG) neurons by binding to terminal alpha-galactose on glycoproteins and glycolipids. The enzymes alpha(1,3)galactosyltransferase (1,3GT) and isoglobotriaosylceramide synthase (iGb3S) synthesize the galactose-alpha(1,3)-galactose group, which is the most common carbohydrate containing terminal alpha-galactose. 1,3GT preferentially glycosylates proteins whereas iGb3S glycosylates lipids. We generated antibodies against rat 1,3GT and iGb3S that were used for immunohistochemical staining of DRG cells. Virtually all neurons that bound IB4 expressed both enzymes, suggesting that IB4 binds to both glycoproteins and glycolipids in IB4-positive neurons. 1,3GT immunoreactivity was observed in small and medium-sized neurons and satellite cells. iGb3S immunoreactivity was observed in neurons of varying sizes. Many neurons that expressed these enzymes did not bind IB4. Additionally, the majority of neurons that expressed substance P expressed both enzymes but did not bind IB4. Ultrastructual studies revealed that 1,3GT was predominantly associated with the Golgi apparatus, whereas iGb3S was found near the Golgi apparatus and in large, clear vesicles throughout the soma. These data suggest that, although expression of 1,3GT and/or iGb3S appears to be necessary for IB4 binding, expression of these enzymes is not sufficient to impart IB4 binding.

Cone beam computed tomographic findings in refractory chronic suppurative osteomyelitis of the mandible.

AIMS: To report the imaging features of osteomyelitis of the mandible in various two-dimensional multiplanar and three-dimensional reformations using cone beam computed tomography (CBCT). METHODS: The images were 12-bit DICOM files acquired with a 10cm field of view and voxel resolution of 0.4mm. Two-dimensional multiplanar reformatted reconstructions included coronal, "panoramic" (variable thickness), and serial cross-sections. Three-dimensional reconstructions included surface renderings. Images were presented to referring oral and maxillofacial surgeons in "real time" immediately after acquisition. RESULTS: The features of mandibular osteomyelitis seen on CBCT included: a peripheral sclerotic rim, cortical layering (involucrum), central loss of trabecular pattern with internal round radiolucent resorptive tracts, minimal jaw expansion, and reduction of the alveolar cortex. Sequestra were occasionally evident. The history and presentation of each case on CBCT were consistent with osteomyelitis of the mandible; however, the clinical differential diagnosis in each case had included malignancy. The definitive diagnosis was confirmed by histological examination of biopsy specimens. Two of the three cases were patients who had been treated with bisphosphonates. CONCLUSION: CBCT facilitated comprehensive and dynamic imaging of the jaws based on surgical consultation, rather than inflexible imaging protocols. CBCT images guided operative planning.

Identification of some lectin IB4 binding proteins in rat dorsal root ganglia.

Lectins are proteins that bind to glycoproteins and glycolipids. The isolectin Griffonia simplicifolia I-B4 (IB4) recognizes terminal alpha-galactose and binds to a subset of small and medium-sized neurons in the dorsal root ganglia (DRG). Using one and two-dimensional gel electrophoresis, we have identified several proteins that bind IB4 in sciatic nerve, dorsal horn, and DRG. Treatment with the enzyme alpha-galactosidase reduces IB4 binding, strongly suggesting the binding is specific for the IB4 epitope. Mass spectrometric analysis of tryptic digests of alpha-galactosidase sensitive bands identified three proteins that bind IB4: the laminin beta 2 chain and the light and medium subunits of neurofilaments.