Objective: The far lateral, extreme lateral infrajugular transcondylar–transtubercular exposure (ELITE), and extreme lateral transcondylar transodontoid (ELTO) approaches provide access to lesions of the foramen magnum, inferolateral-to-mid clivus, and ventral pons and medulla. A subset of pathologies in this region requires manipulation of the vertebral artery (VA)-dural interface. Although a cuff of dura is commonly left on the artery to avoid vessel injury during these approaches, there are varying descriptions on the degree of VA-dural separation that is safely achievable. We herein provide a detailed histologic analysis of the VA-dural junction to guide microsurgical technique for posterolateral skull base approaches.
Sarcomas are rare malignancies of mesenchymal lineage with more than 100 specific types and many benign potential mimics. In situ and precursor lesions are generally not described and thus much of molecular pathology in this field concentrates on mol
Correction to: Genetics in Medicine19:2017; https://doi.org/10.1038/gim.2017.37, published online 11 May 2017 There were errors in the author listing such that consortium group of authors was not named individually. The corrected author list is: Sienna Aguilar, MS; Swaroop Aradhya, PhD, FACMG; Daniel Beltran, PhD; Brandon Bunker, PhD; Amy Daly, MS; Anne Deucher, MD; Tali Ekstein, MS; Ali Entezam, PhD; Karl Erhard, PhD; Ed Esplin MD, PhD, FACMG, FACP; Jennifer Fulbright, MS; Amy Fuller, MS; Kristen McDonald Gibson, PhD, FACMG; Tina Hambuch, PhD, FACMG; Rachel Harte, PhD; Christy Hartshorne, MS; Eden Haverfield, PhD, FACMG; Nastaran Heidari, PhD; Michelle Hogue, MS; Daniela Iacoboni, MS; Britt Johnson, PhD, FACMG; Hio Chung Kang, PhD; Rachel Lewis, PhD; Shiloh Martin, PhD; Sarah McCalmon, PhD; Scott Michalski, MS; Cindy Morgan, MS; Laura Murillo, PhD; Piper Nicolosi, PhD; Karen Ouyang, PhD, FACMG; Carolina Pardo, PhD; Rita Quintana, PhD; Marina Rabideau, MS; Darlene Riethmaier, MS; Amanda Stafford, PhD; Jackie Tahiliani, MS; Chris Tan, MS; S. Paige Taylor, PhD; Shu-Huei Wang, PhD; Hannah White, MS; Ian Wilson, PhD, FACMG; Tom Winder, PhD, FACMG; and Michelle K. Zeman, PhD. The original article can be found online at https://doi.org/10.1038/gim.2017.37. Sherloc: a comprehensive refinement of the ACMG–AMP variant classification criteriaGenetics in MedicineVol. 19Issue 10PreviewThe 2015 American College of Medical Genetics and Genomics–Association for Molecular Pathology (ACMG–AMP) guidelines were a major step toward establishing a common framework for variant classification. In practice, however, several aspects of the guidelines lack specificity, are subject to varied interpretations, or fail to capture relevant aspects of clinical molecular genetics. A simple implementation of the guidelines in their current form is insufficient for consistent and comprehensive variant classification. Full-Text PDF Open Access
The distinction of multifocal versus multicentric gliomas can conceivably have important therapeutic implications. We present a 27-year-old man with two radiologically distinct non-enhancing infiltrative masses in the anterior frontal lobe and the posterior temporoparietal region. No intervening disease was evident on MRI modalities; the lesions were stable over a period of many months. He underwent two separate resections a few months apart. Given the question of whether his tumors represented two de novo primary multicentric tumors or one multifocal tumor, single nucleotide polymorphism (SNP) array karyotyping and in situ hybridization studies were performed on both tumors. The two tumor profiles looked remarkably similar, histologically and genetically: both were anaplastic astrocytomas with a common 33Mb gain/ amplification of 8q23.3-q24.3, including MYC amplification, suggesting a monoclonal origin. The temporoparietal neoplasm showed several additional genetic alterations. This case illustrates that even with today's advanced neuroimaging modalities, extensive radiologically invisible tumor may be present between seemingly separate sites of glioma involvement. Thus modern global genomic studies of such tumors may help distinguish whether multiple tumors represent one extensive neoplasm with microscopically invasive disease or multiple genetically distinct tumors.
Oncocytoma, chromophobe renal cell carcinoma (chRCC), and the eosinophilic variant of clear cell RCC (ccRCC) are morphologically similar tumors with significantly different clinical courses. These renal tumor subtypes show characteristic structural genetic changes; however, the mRNA expression patterns of oncocytoma and chRCC are strikingly similar. MicroRNAs (miRNA) are small RNA molecules that regulate the expression of many genes and have been shown to be useful for tumor classification and identification. The miRNA expression was analyzed from formalin-fixed paraffin-embedded tissue in 5 cases each of oncocytoma, ccRCC, papillary RCC, chRCC, and 4 normal kidney tissues using microarrays. Affymetrix single-nucleotide polymorphism arrays were used to detect chromosomal imbalances in each of the tumors. Eighteen miRNAs were significantly different among the 4 tumor types. The microRNA miR-21, a known oncogenic miRNA, was found to be upregulated in papillary and clear cell carcinomas. Four miRNAs could differentiate oncocytomas from chRCCs and the 3 could differentiate papillary RCC from ccRCC, including miR-126, a known vasculogenic miRNA. Of the 18 differentially expressed miRNAs, only 2 correlated with copy number changes in the chromosomal region harboring these genes. One tumor, originally diagnosed as an oncocytoma by morphology, showed a virtual karyotype and miRNA expression pattern consistent with chromophobe carcinoma. Further investigation of the tumor showed vascular invasion. Our study suggests that miRNA expression can be used to differentiate the common subtypes of renal epithelial neoplasms but further validation is necessary. In addition, the lack of correlation between miRNA expression and virtual karyotype suggests a non-copy-number-related mechanism for miRNA gene expression regulation in renal neoplasia.
Gliosarcoma, a biphasic tumor with both mesenchymal and glial elements, is typically considered a variant of astrocytoma (glioblastoma), WHO Grade IV. A 57-year-old man presented with altered mental status and was found to have a large right frontal mass. Biopsy and subsequent subtotal resection revealed a WHO Grade II oligodendroglioma with classic histological features, expression of IDH1 R132H mutant protein, and chromosome 1p19q co-deletion. Fifteen months later, the patient developed recurrent tumor composed of intersecting fascicles of spindled cells with necrosis and a high mitotic index. The recurrent tumor stained for both mesenchymal and glial elements, consistent with the diagnosis of gliosarcoma, and showed retained IDH1 R132H expression. By FISH analysis, the gliosarcoma showed no evidence of 1p19q co-deletion. We performed SNP arrays and detailed SNP analysis of both the oligodendroglioma and the gliosarcoma. This demonstrated loss of heterozygosity (LOH) of chromosomes 1 and 19 in the gliosarcoma with retention of the same full-length chromosomes 1 and 19 found intact in the oligodendroglioma. Not surprisingly, the gliosarcoma harbored multiple additional alterations, consistent with clonal evolution. There have been only rare reports of sarcomatous transformation of oligodendroglioma ("oligosarcoma") and most were published prior to the development of modern genetic modalities. Here we present a case with detailed genetic evidence that suggests that mesenchymal metaplasia sarcomatous transformation is possible in classic oligodendrogliomas with 1p19q codeletions.
Using a Drosophila model of Alzheimer's disease (AD), we systematically evaluated 67 candidate genes based on AD-associated genomic loci (P < 10−4) from published human genome-wide association studies (GWAS). Genetic manipulation of 87 homologous fly genes was tested for modulation of neurotoxicity caused by human Tau, which forms neurofibrillary tangle pathology in AD. RNA interference (RNAi) targeting 9 genes enhanced Tau neurotoxicity, and in most cases reciprocal activation of gene expression suppressed Tau toxicity. Our screen implicates cindr, the fly ortholog of the human CD2AP AD susceptibility gene, as a modulator of Tau-mediated disease mechanisms. Importantly, we also identify the fly orthologs of FERMT2 and CELF1 as Tau modifiers, and these loci have been independently validated as AD susceptibility loci in the latest GWAS meta-analysis. Both CD2AP and FERMT2 have been previously implicated with roles in cell adhesion, and our screen additionally identifies a fly homolog of the human integrin adhesion receptors, ITGAM and ITGA9, as a modifier of Tau neurotoxicity. Our results highlight cell adhesion pathways as important in Tau toxicity and AD susceptibility and demonstrate the power of model organism genetic screens for the functional follow-up of human GWAS.
5009 Background: Inherited risk for prostate cancer (PCa) is potentially associated with more aggressive disease. Recent data indicate that DNA repair gene abnormalities may be much more common than previously appreciated, especially BRCA2, ATM, CHEK2, BRCA1, RAD51D, and PALB2. Herein, we investigate the efficacy of a targeted gene panel in men with PCa and evaluate clinical factors in relationship to current guidelines for genetic screening. Methods: DNA sequencing and exon-level copy number analysis were performed in 1158 PCa patients (pts) between 2013 and 2016 at a commercial diagnostic laboratory. The genes requisitioned varied but consistently included 14 genes on a hereditary PCa panel, most of which were DNA repair genes. Evaluation included Gleason scores and eligibility for genetic screening based on any NCCN testing criteria in pts with positive findings (pathogenic, likely pathogenic, and risk allele). Results: Pathogenic findings were identified in 199 of 1158 (17.2%) pts, 13 pts (1.0%) had two variants. Roughly 75% of detected variants were in genes on the hereditary PCa panel, of which 34.4% were BRCA1/2. Positive variants in HOXB13, a gene associated only with PCa risk, were identified in eight (3.8%) pts. DNA mismatch repair variants, alterations with substantial known therapeutic implications, were detected in 1.7% of samples. A total of 12.4% of pts with Gleason scores of ≤6, compared with 15.4% of those with scores of ≥7 had a pathogenic variant. Within this cohort, 126 (63%) patients with positive results were eligible for genetic testing based on currently available NCCN guidelines, whereas 73 (37%) would not have qualified. Conclusions: Current NCCN guidelines and Gleason scores cannot be used to reliably stratify PCa pts for the presence/absence of pathogenic germline variants. Most positive results identified in this study have important management implications for pts and their families. The percentage of pts with germline variants who did not meet current genetic screening criteria underscores the need for revisiting current guidelines which cannot, at this time, reliably be used to predict pathologic findings on genetic testing.
