Resolution of Middle Fossa Arachnoid Cyst after Minor Head Trauma - Stages of Resolution on MRI: Case Report and Literature Review.

Arachnoid cysts (ACs) are frequently encountered in pediatric neurosurgical practice. Their natural history and optimum treatment are not well determined. The authors describe a resolution of asymptomatic middle fossa AC after trivial head trauma in a 7-year-old child. Intracystic bleeding was noticed on interval MRI. Serial MRI follow-up demonstrates stages of resolution of the AC that did not require surgical intervention. Few cases of nonsurgical AC disappearance have been reported, much fewer with trauma as a triggering factor. Here, we present the stages of resolution in images.