Giant arachnoid granulation in a child with benign intracranial hypertension: an unusual case

Abstract

We report a case of giant arachnoid granulation involving the anterior superior sagittal sinus in a 6-year-old girl who presented with benign intracranial hypertension. Clinicians should be aware of this rare anatomic variant to avoid unnecessary invasive procedures or examinations in children with benign intracranial hypertension.

Giant Arachnoid Granulations: A Systematic Literature Review

“…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.…”

“…Of the 147 persons with documented gender, GAGs involved 80 (54%) females and 67 (46%) males and were similarly distributed across sex (1.2:1 female-to-male ratio) ( Table 2 ). The afflicted persons included infants [ 15 ], children [ 10 , 16 , 17 , 18 , 19 , 20 ], adolescents [ 17 , 21 , 22 , 23 , 24 ], and adults across a wide age spectrum [ 10 , 15 , 45 ] (range, 0.33 to 91 years; mean, 43 ± 20 years). Interestingly, one pediatric case was reported by parents since birth [ 16 ].…”

“…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 ].…”

“…Several individuals experienced misdiagnosis or delayed diagnosis of GAG [ 7 , 22 , 43 , 45 ]. Since symptoms were sometimes initially interpreted as subacute or chronic DVS thrombosis, hypercoagulability workup and medical treatment were initiated to manage symptoms of presumed coagulopathy, infection, or related processes [ 12 , 14 , 19 , 22 , 23 , 25 , 26 , 33 , 35 , 36 , 39 , 41 , 43 ]. Patients were treated with acetazolamide [ 19 , 32 , 41 , 43 ], NSAID, anticephalgic medication, or other analgesia [ 12 , 23 , 33 , 34 , 43 ], other anticoagulants [ 22 , 35 , 36 ], antiepileptics [ 39 ], furosemide [ 41 ], mannitol [ 41 ], prednisolone [ 25 ], decongestants [ 14 ], and/or antibiotics [ 14 , 44 ] (each in 1 to 4 of 169 patients, or <3%).…”

An unusual vermiform giant arachnoid granulation

“…Although the association of arachnoid granulations with patient symptoms remains unclear [13], [14], the importance of distinguishing arachnoid granulations from dural sinus pathology is essential in making the right diagnoses and preventing inappropriate therapy. Arachnoid granulations are considered incidental findings that represent a normal anatomic entity commonly found in the adult population [15].…”