Giant arachnoid granulation: differential diagnosis of acute headache

Australas Radiol. 2007 Oct;51 Spec No.:B18-20. doi: 10.1111/j.1440-1673.2007.01823.x.


We present a case of intense, rapidly evolving headache clinically mimicking meningitis, subarachnoid haemorrhage or venous sinus thrombosis. Clinical examination, standard blood work and central nervous system studies were non-contributory and effectively ruled out these diagnoses. Cranial multidetector CT studies before and after application of intravenous contrast medium performed prior to lumbar tap disclosed a non-enhancing ovoid mass filling the superior sagittal sinus. This lesion posed a differential to venous sinus thrombosis, but ultimately fulfilled the criteria of a giant arachnoid granulation. The imaging characteristics and differential diagnosis of giant arachnoid granulations are discussed.

Publication types

  • Case Reports

MeSH terms

  • Acute Disease
  • Adult
  • Arachnoid / diagnostic imaging*
  • Brain Diseases / diagnostic imaging*
  • Diagnosis, Differential
  • Headache / diagnosis*
  • Humans
  • Male
  • Tomography, X-Ray Computed*