Multinodular and vacuolating neuronal tumor of the cerebrum is a recently reported benign, mixed glial neuronal lesion that is included in the 2016 updated World Health Organization classification of brain neoplasms as a unique cytoarchitectural pattern of gangliocytoma. We report 33 cases of presumed multinodular and vacuolating neuronal tumor of the cerebrum that exhibit a remarkably similar pattern of imaging findings consisting of a subcortical cluster of nodular lesions located on the inner surface of an otherwise normal-appearing cortex, principally within the deep cortical ribbon and superficial subcortical white matter, which is hyperintense on FLAIR. Only 4 of our cases are biopsy-proven because most were asymptomatic and incidentally discovered. The remaining were followed for a minimum of 24 months (mean, 3 years) without interval change. We demonstrate that these are benign, nonaggressive lesions that do not require biopsy in asymptomatic patients and behave more like a malformative process than a true neoplasm.

We would like to thank Nikki Jahnke, Managing Editor of the Cochrane Cystic Fibrosis and Genetic Disorders Group for her support. We would also like to thank Dr Claire Shovlin for providing an in-depth peer review.

Susceptibility-weighted imaging (SWI) provides invaluable insight into glioma pathophysiology and internal tumoral architecture. The physical contribution of intratumoral susceptibility signal (ITSS) may correspond to intralesional hemorrhage, calcification, or tumoral neovascularity. In this review, we present emerging evidence of ITSS for assessment of intratumoral calcification, grading of glioma, and factors influencing the pattern of ITSS in glioblastoma. SWI phase imaging assists in identification of intratumoral calcification that aids in narrowing the differential diagnosis. Development of intratumoral calcification posttreatment of glioma serves as an imaging marker of positive therapy response. Grading of tumors with ITSS using information attributed to microhemorrhage and neovascularity in SWI correlates with MR perfusion parameters and histologic grading of glioma and enriches preoperative prognosis. Quantitative susceptibility mapping may provide a means to discriminate subtle calcifications and hemorrhage in tumor imaging. Recent data suggest ITSS patterns in glioblastoma vary depending on tumoral volume and sublocation and correlate with degree of intratumoral necrosis and neovascularity. Increasingly, there is a recognized role of obtaining contrast-enhanced SWI (CE-SWI) for assessment of tumoral margin in high-grade glioma. Significant higher concentration of gadolinium accumulates at the border of the tumoral invasion zone as seen on the SWI sequence; this results from contrast-induced phase shift that clearly delineates the tumor margin. Lastly, absence of ITSS may aid in differentiation between high-grade glioma and primary CNS lymphoma, which typically shows absence of ITSS. We conclude that SWI and CE-SWI are indispensable tools for diagnosis, preoperative grading, posttherapy surveillance, and assessment of glioma.

While no randomised controlled trials of this treatment are included in this review, a number of observational studies have suggested embolisation therapy has benefits. However, randomised controlled trials are not always feasible on ethical grounds. In the absence of randomised controlled trials, a standardised approach to reporting, as well as long-term follow-up through registry studies can help to improve the safety and outcome of embolisation for pulmonary arteriovenous malformations. Quality of the evidence We have not been able to present any evidence from randomised controlled trials in this version of the review.

Venous cutdown versus the Seldinger technique for placement of totally implantable venous access ports.

Spread of microabscesses along white matter tracts and frequent trigeminal nerve involvement are unique imaging characteristics of CNS melioidosis. These findings may provide insight into potential mechanisms for B. pseuodomallei entry into the CNS through direct axonal transport in cranial nerves bypassing the blood brain barrier. Prompt recognition of the neuroimaging features of this potentially fatal infection may allow for early microbiological culture and treatment.

Primary central nervous system vasculitis (PCNSV) is a poorly understood neuroinflammatory disease of the CNS affecting the intracranial vasculature. Although PCNSV classically manifests as a multifocal beaded narrowing of the intracranial vessels, some patients may not have angiographic abnormalities. A rare subset of patients with PCNSV present with masslike brain lesions mimicking a neoplasm. In this article, we retrospectively review 10 biopsy-confirmed cases of tumefactive PCNSV (t-PCNSV). All cases of t-PCNSV in our series that underwent CTA or MRA were found to have normal large and medium-sized vessels. T-PCNSV had a variable MR imaging appearance with most cases showing cortical/subcortical enhancing masslike lesion (70%), often with microhemorrhages (80%). Diffusion restriction was absent in all lesions. In summary, normal vascular imaging does not exclude the diagnosis of t-PCNSV. Advanced imaging techniques including MR perfusion and MR spectroscopy failed to demonstrate specific findings for t-PCNSV but assisted in excluding neoplasm in the differential diagnosis. Biopsy remains mandatory for definitive diagnosis.ABBREVIATIONS: PCNSV ¼ primary central nervous system vasculitis; t-PCNSV ¼ tumefactive PCNSV; ABRA ¼ amyloidb -associated angiitis; CAA-RI ¼ cerebral amyloid angiopathy-related inflammation; ESR ¼ erythrocyte sedimentation rate; MRP ¼ MR perfusion; CRP ¼ C-reactive protein; PCR ¼ polymerase chain reaction; VWI ¼ vessel wall imaging; PCNSL ¼ primary CNS lymphoma P rimary central nervous system vasculitis (PCNSV) is a poorly understood neuroinflammatory disease involving intracranial vessels. [1][2][3][4][5] The typical radiologic manifestation of PCNSV is multifocal beading of the large and medium-sized intracranial vessels. An underrecognized and rarer subset of PCNSV, approximately 5%-29%, can present with "masslike" or "tumefactive" lesions mimicking a neoplasm. 3,4,[6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25] To date, imaging features of tumefactive PCNSV (t-PCNSV) have not been well described and definitive diagnosis can only be made confidently on histopathology. [5][6][7][8][9][10] In this article, we performed a retrospective review of 10 histopathologically proved cases of t-PCNSV and analyzed pertinent imaging features with histopathologic correlation. CASE SERIES Case SelectionWe performed a retrospective pathology data base search by using the keywords "brain biopsy" and "vasculitis" in histopathology reports from July 2010-December 2018 at a single institution. Exclusion criteria included patients with histopathology findings of amyloid-beta (Ab )-associated angiitis (ABRA) or cerebral amyloid angiopathy-related inflammation (CAA-RI), and infectious CNS vasculitis. Finally, we identified 6 patients who had a final diagnosis of t-PCNSV from this institution. The other 4 patients with t-PCNSV were collected from the imaging and histopathology archives of the contributing authors from 2 other institutions.All 10 patients presented with masslike brain...

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