Faculty Bibliography

BACKGROUND AND PURPOSE/OBJECTIVE:Patients with the Coronavirus Disease of 2019 (COVID-19) are at increased risk for thrombotic events and mortality. Various anticoagulation regimens are now being considered for these patients. Anticoagulation is known to increase the risk for adverse bleeding events, of which intracranial hemorrhage (ICH) is one of the most feared. We present a retrospective study of 33 patients positive for COVID-19 with neuroimaging-documented ICH and examine anticoagulation use in this population. METHODS:Patients over the age of 18 with confirmed COVID-19 and radiographic evidence of ICH were included in this study. Evidence of hemorrhage was confirmed and categorized by a fellowship trained neuroradiologist. Electronic health records were analyzed for patient information including demographic data, medical history, hospital course, laboratory values, and medications. RESULTS:We identified 33 COVID-19 positive patients with ICH, mean age 61.6 years (range 37-83 years), 21.2% of whom were female. Parenchymal hemorrhages with mass effect and herniation occurred in 5 (15.2%) patients, with a 100% mortality rate. Of the remaining 28 patients with ICH, 7 (25%) had punctate hemorrhages, 17 (60.7%) had small- moderate size hemorrhages, and 4 (14.3%) had a large single site of hemorrhage without evidence of herniation. Almost all patients received either therapeutic dose anticoagulation (in 22 [66.7%] patients) or prophylactic dose (in 3 [9.1] patients) prior to ICH discovery. CONCLUSIONS:Anticoagulation therapy may be considered in patients with COVID-19 though the risk of ICH should be taken into account when developing a treatment regimen.

The cavernous sinus is a complex structure susceptible to a wide variety of vascular, neoplastic and inflammatory pathologies. Vascular pathologies include ICA aneurysms, carotid-cavernous fistulas, cavernous sinus thrombosis, and cavernous hemangioma. Neoplasms that involve the cavernous sinus include pituitary adenoma, meningioma, schwannoma, lymphoma, perineural tumor spread, metastases, and direct tumor invasion. Infectious and inflammatory diseases include Tolosa-Hunt syndrome, sarcoidosis, granulomatosis with polyangiitis, IgG-4 related disease and invasive fungal infections. In this article, we review the clinical and imaging findings of a number of pathologies involving the cavernous sinus, focusing on key features that can narrow the differential diagnosis and, in some cases, support a particular diagnosis.

Background/UNASSIGNED:Glioma is a family of primary brain malignancies with limited treatment options and in need of novel therapies. We previously demonstrated that the adhesion G protein-coupled receptor GPR133 (ADGRD1) is necessary for tumor growth in adult glioblastoma, the most advanced malignancy within the glioma family. However, the expression pattern of GPR133 in other types of adult glioma is unknown. Methods/UNASSIGNED:We used immunohistochemistry in tumor specimens and non-neoplastic cadaveric brain tissue to profile GPR133 expression in adult gliomas. Results/UNASSIGNED:We show that GPR133 expression increases as a function of WHO grade and peaks in glioblastoma, where all tumors ubiquitously express it. Importantly, GPR133 is expressed within the tumor bulk, as well as in the brain-infiltrating tumor margin. Furthermore, GPR133 is expressed in both isocitrate dehydrogenase (IDH) wild-type and mutant gliomas, albeit at higher levels in IDH wild-type tumors. Conclusion/UNASSIGNED:The fact that GPR133 is absent from non-neoplastic brain tissue but de novo expressed in glioma suggests that it may be exploited therapeutically.

Neurologic manifestations of the novel coronavirus SARS-CoV-2 infection have received wide attention, but the mechanisms remain uncertain. Here, we describe computational data from public domain RNA-seq datasets and cerebrospinal fluid data from adult patients with severe COVID-19 pneumonia that suggest that SARS-CoV-2 infection of the central nervous system is unlikely. We found that the mRNAs encoding the ACE2 receptor and the TMPRSS2 transmembrane serine protease, both of which are required for viral entry into host cells, are minimally expressed in the major cell types of the brain. In addition, CSF samples from 13 adult encephalopathic COVID-19 patients diagnosed with the viral infection via nasopharyngeal swab RT-PCR did not show evidence for the virus. This particular finding is robust for two reasons. First, the RT-PCR diagnostic was validated for CSF studies using stringent criteria; and second, 61% of these patients had CSF testing within 1 week of a positive nasopharyngeal diagnostic test. We propose that neurologic sequelae of COVID-19 are not due to SARS-CoV-2 meningoencephalitis and that other etiologies are more likely mechanisms.

IDH1/2 mutations are early drivers present in diverse human cancer types arising in various tissue sites. IDH1/2 mutation is known to induce a global hypermethylator phenotype. However, the effects on DNA methylation across IDH mutant cancers and functionally different genome regions, remain unknown. We analyzed DNA methylation data from IDH1/2 mutant acute myeloid leukemia, oligodendroglioma, astrocytoma, solid papillary breast carcinoma with reverse polarity, sinonasal undifferentiated carcinoma and cholangiocarcinoma, which clustered by their embryonal origin. Hypermethylated common probes affect predominantly gene bodies while promoters in IDH1/2 mutant cancers remain unmethylated. Enhancers showed global hypermethylation, however commonly hypomethylated enhancers were associated with tissue differentiation and cell fate determination. We demonstrate that some chromosomes, chromosomal arms and chromosomal regions are more affected by IDH1/2 mutations while others remain resistant to IDH1/2 mutation induced methylation changes. Therefore IDH1/2 mutations have different methylation effect on different parts of the genome, which may be regulated by different mechanisms.

BACKGROUND: There is no effective therapy for patients (pts) with IDH-mutant gliomas that progress after RT and chemotherapy. At time of progression, these tumors have often transformed to glioblastoma (GBM) and have increased numbers of somatic mutations, i.e. have a ?hypermutator phenotype?. We hypothesized that there is synergistic efficacy of Avelumab (anti-PD-L1) combined with HFRT in pts with secondarily trans- formed IDH-mutant GBMs. Safety-lead-in results will be presented.
METHOD(S): This is a phase II, open-label, single-arm, multicenter study of Avelumab with HFRT in adults with transformed IDH-mutant GBM who previously received RT and TMZ and/or PCV. All pts received Avelumab 10 mg/kg IV followed at Day 8 by HFRT (25 Gy in 5 daily 5-Gy fractions) and then Avelumab 10 mg/kg IV every 2 weeks. A 3 + 3 design was used for a 6-patient safety-lead-in cohort. Adverse events were recorded according to CTCAE.
RESULT(S): Six pts (F=4, M=2) with a median age= 45.5 yrs (range 31.5-54.4 yrs) were enrolled in the safety-lead-in cohort. No DLT was observed. Grade >= 3 AEs included increased cerebral edema (3 pts), hyponatremia (1 pt) and worsening hemiparesis (3 pts). Grade <= 2 AEs included nausea, hypothyroidism, lymphopenia, thrombocytopenia, transaminase elevation, and fever/chills. Median follow-up time was 8.9 mo. Best treatment response was SD in 1 patient. At time of last follow-up all pts have discontinued treatment for PD. Median PFS was 4.2 mo (range 1.4-5.7). Median OS was 10.1 (range 6.8-21+) mo. 4 pts (67%) died, 2 pts remain alive in follow-up at 6.9 and 21.6 months after treatment initiation. The study was closed after the safety lead-in completed enrollment due to slow accrual.
CONCLUSION(S): Avelumab combined with HFRT was tolerable without dose-limiting toxicity in this safety-lead-in cohort of adult patients with transformed IDH-mutant GBM. Further studies are necessary to determine efficacy of this treatment regimen

BACKGROUND: While most hemangioblastomas (~70%) are sporadic and occur predominantly in the cerebellum, they may present as well as familial form associated with von Hippel-Lindau (VHL) syndrome, an autosomal dominant disorder caused by germline mutations of the VHL gene that trigger nuclear translocation of hypoxia-inducible factor (HIF)- 1alpha and angiogenesis. Although inactivation of VHL, a tumor suppressor gene, has been observed in hemangioblastomas, the underlying pathogenic mechanisms responsible for familial and sporadic hemangioblastomas remain incompletely understood.
METHOD(S): Whole exome sequencing of cerebellar hemangioblastoma tumors and matched blood leukocytes from 24 patients, age 24-63, was performed. After preparation and amplification of barcoded libraries, exomes were captured using Kapa Biosystems methodology and paired-end sequenced on Illumina HiSeq 2500 to an average 100-fold coverage. Following read alignment to hg19 genome, tumor and germline (leukocyte) sequences were compared, and pathogenic single nucleotide variants (SNVs) identified and validated by re-sequencing followed by pathway analysis. Additionally, tumor RNA isolated using Maxwell Promega was sequenced on Illumina instrument and the expression counts determined and normalized.
RESULT(S): We found 314 pathogenic and/or highly deleterious mutations (both germline and somatic) with a median of 13 mutations per patient. Five patients had VHL syndrome (germline VHL mutation) and 4 carried somatic VHL mutations. Among the VHL tumors, 82 mutations were identified, including HNF1B, NOTCH1 and TCF7L1, suggesting a potential contribution of altered RNA metabolism based upon pathway analysis. Among all hemangioblastomas, germline growth factor receptor variants (FGFR4 p.G388R (14/23 (61%) patients), IGF1R, PDGFRA and TYK2) known to activate STAT3 signaling and induce HIF-1alpha and angiogenesis, were identified. Non-hierarchical clustering of RNA sequencing data revealed two transcriptionally-distinct subtypes of hemangioblastomas.
CONCLUSION(S): Our findings indicate that hemangioblastomas can also occur by germline mutations known to activate STAT3 signaling, which may have significant implication in genetic testing and counseling of patients with hemangioblastomas

Melanoma in the head and neck is known to metastasize to cranial nerves. Prompt treatment is critical for preventing progression and reducing neuropathy. We report a patient who presented with cranial neuropathy related to a malignant skull base lesion that originated as lentigo maligna. The diagnosis was challenging, requiring two surgeries to obtain tissue and neither biopsy leading to a definitive diagnosis. Pathological analyses demonstrated positive immunoreactivity for SOX10 and S100, preservation of H3K27me3, and PTEN and STK11 mutations. The patient was managed with Gamma Knife Radiosurgery and combination immunotherapy. Imaging at 9 months post-SRS showed resolution of the mass lesion. Clinically, the patient has occasional left-sided facial pain requiring no medication and denies facial numbness. We favor a diagnosis of desmoplastic neurotropic melanoma due to the neurotropic spread and response to melanoma-targeted immunotherapy.