Giant arachnoid granulations

Sunbulli, Mohammed; Zak, Imad

doi:10.1212/01.wnl.0000156361.68619.b8

Cited by 5 publications

(8 citation statements)

References 9 publications

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“…5,6 More recently, so-called giant AGs ranging from 1 to 2.4 cm have been reported. 6,11,13,[17][18][19][20] CSF-like attenuation on CT or fluid that parallels all MR images has been a conventional diagnostic criterion for AGs, though isolated exceptions to this general rule have been reported in the literature. Ikushima et al 3 showed that 10% of AGs averaging 5.1 mm in diameter were slightly hyperintense to CSF on FLAIR imaging.…”

Section: Discussionmentioning

confidence: 99%

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“Giant” Arachnoid Granulations Just Like CSF?: NOT!!

Trimble¹,

Harnsberger²,

Castillo³

et al. 2010

AJNR Am J Neuroradiol

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"Giant" AGs (>1 cm) are uncommon and can be misdiagnosed as venous sinus pathology such as a neoplasm or thrombosis. Seventeen patients with a total of 19 venous sinus AGs of >1 cm were collected from contributing authors. MR imaging was available for all AGs; CT, for 5/19; and DSA, for 7/19. Intra-AG fluid was compared with CSF in subarachnoid spaces. Nonfluid AG tissue was compared with gray matter. Diagnosis was based on imaging findings. Fluid within giant AGs did not follow CSF signal intensity on at least 1 MR image in nearly 80% (15/19) of AGs. Nine of these 15 AGs had CSF-incongruent signal intensity on ≥2 MR images. CSF-incongruent signal intensity was seen in 8/8 AGs on FLAIR, 7/10 on precontrast T1WI, 13/19 on T2WI, and 8/14 on contrast-enhanced T1WI. Nonfluid signal intensity was present in 18/19 AGs and varied from absent/hypointense (intra-AG flow voids) to gray matter isointense (stromal tissue).

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Section: Discussionmentioning

confidence: 99%

“…While some large AGs may cause dural venous sinus pressure gradients and headaches, most are usually asymptomatic and incidental findings on imaging studies. 17,18,20 They should be distinguished from other more ominous pathologies such as thrombus and neoplasm, and invasive studies such as biopsy should be assiduously avoided.…”

Section: Discussionmentioning

confidence: 99%

“Giant” Arachnoid Granulations Just Like CSF?: NOT!!

Trimble¹,

Harnsberger²,

Castillo³

et al. 2010

AJNR Am J Neuroradiol

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“…The published literature from 1973 to 2023 yielded 41 publications describing GAGs in 169 persons [ 3 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 ] ( Table S1 ). This incorporated reports of 146 persons each with a single GAG; 21 persons with at least two GAGs [ 7 , 8 , 9 , 10 , 11 ]; and 2 persons who each exhibited “multiple” GAGs, with three [ 12 ] or four [ 8 ] GAGs being discernible on presented imaging.…”

Section: Resultsmentioning

confidence: 99%

“…Diagnosis of GAG on imaging workup ( Table S1 ) was accomplished by visualization of round-to-ovoid, irregular or oblong, unilocular or multilocular cystic-appearing structures with or without internal septations, and with internal CSF-like density or signal intensity and communication with the subarachnoid space on MRI with and/or without contrast [ 8 , 13 , 15 , 17 , 19 , 20 , 22 , 23 , 24 , 25 , 26 , 28 , 30 , 31 , 36 , 37 , 38 , 39 ] ( Figure 4 A), MR angiogram/venogram [ 10 , 23 , 25 , 34 , 35 , 36 , 39 , 40 , 41 , 42 ], CT with and/or without contrast, or CT angiogram [ 8 , 21 , 25 , 27 , 28 , 31 , 34 , 35 ] ( Figure 4 B). GAGs were also identified as well-delineated focal calvarial defects on plain X-ray [ 13 , 15 ] or as focal filling defects within the DVS on conventional angiography and/or on cross-sectional studies [ 11 ].…”

Section: Resultsmentioning

confidence: 99%

Giant Arachnoid Granulations: A Systematic Literature Review

Mehta,

Mehta

2023

IJMS

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Giant arachnoid granulations (GAGs) are minimally investigated. Here, we systematically review the available data in published reports to better understand their etiologies, nomenclature, and clinical significance. In the literature, 195 GAGs have been documented in 169 persons of varied ages (range, 0.33 to 91 years; mean, 43 ± 20 years; 54% female). Prior reports depict intrasinus (i.e., dural venous sinus, DVS) (84%), extrasinus (i.e., diploic or calvarial) (15%), and mixed (1%) GAG types that exhibit pedunculated, sessile, or vermiform morphologies. GAG size ranged from 0.4 to 6 cm in maximum dimension (mean, 1.9 ± 1.1 cm) and encompassed symptomatic or non-symptomatic enlarged arachnoid granulations (≥1 cm) as well as symptomatic subcentimeter arachnoid granulations. A significant difference was identified in mean GAG size between sex (females, 1.78 cm; males, 3.39 cm; p < 0.05). The signs and symptoms associated with GAGs varied and include headache (19%), sensory change(s) (11%), and intracranial hypertension (2%), among diverse and potentially serious sequelae. Notably, brain herniation was present within 38 GAGs (22%). Among treated individuals, subsets were managed medically (19 persons, 11%), surgically (15 persons, 9%), and/or by endovascular DVS stenting (7 persons, 4%). Histologic workup of 53 (27%) GAG cases depicted internal inflammation (3%), cystic change consistent with fluid accumulation (2%), venous thrombosis (1%), hemorrhage (1%), meningothelial hyperplasia (1%), lymphatic vascular proliferation (1%), and lymphatic vessel obliteration (1%). This review emphasizes heterogeneity in GAG subtypes, morphology, composite, location, symptomatology, and imaging presentations. Additional systematic investigations are needed to better elucidate the pathobiology, clinical effects, and optimal diagnostic and management strategies for enlarged and symptomatic arachnoid granulation subtypes, as different strategies and size thresholds are likely applicable for medical, interventional, and/or surgical treatment of these structures in distinct brain locations.

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“…Although arachnoid granulations (AGs) were initially described by Antonio Pacchioni more than 300 years ago [1], they are still poorly described, especially in the neuroradiological literature. Two issues draw particular attention: Wrst, the radiological features of AGs, particularly of the socalled giant AGs (GAGs) and its diVerential diagnosis [2][3][4][5][6][7][8][9][10][11], and second, their possible association with various disease processes [12][13][14]. Giant AGs are still a poorly understood distinct entity, seldom mentioned in the neuroanatomical and neuropathological literature.…”

Section: Introductionmentioning

confidence: 99%

Dural arachnoid granulations and “giant” arachnoid granulations

Haybaeck

Silye²,

Soffer

2008

Surg Radiol Anat

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Although arachnoid granulations (AGs) were already described by Antonio Pacchioni more than 300 years ago, two issues draw particular attention: first, the radiological features and differential diagnosis of the so-called giant AGs (GAGs) and second, their possible association with various disease processes. In order to evaluate the frequency, size and normal distribution of GAGs, an anatomical study of the dural sinuses was carried out. It involved all the autopsies performed during the period August 2002-February 2005 and included 651 cases: 306 females and 345 males, aged 13-99 years (mean 69 years). Grossly visible GAGs were identified in 24 cases: 7 females and 17 males, aged 45-92 years (mean 69 years). This is the largest population-based anatomical study on GAGs. It shows that GAGs, in general a rare finding (3.68%), are rather common in the adult population, especially in the elderly (aged >65 years) and that they can reach remarkable size (up to 2.5 cm and more in diameter). Giant AGs should be considered in the radiological differential diagnosis of intradural lesions, particularly those occurring in the transverse sinus of the elderly.

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Giant arachnoid granulations

Cited by 5 publications

References 9 publications

“Giant” Arachnoid Granulations Just Like CSF?: NOT!!

“Giant” Arachnoid Granulations Just Like CSF?: NOT!!

Giant Arachnoid Granulations: A Systematic Literature Review

Dural arachnoid granulations and “giant” arachnoid granulations

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