Spontaneous rupture of an arachnoid cyst in an adult: illustrative case

Arachnoid cysts are common intracranial mass lesions frequently discovered as incidental findings on radiographic imaging. It is routine practice to monitor these lesions as a large majority remain stable. Although traumatic cyst rupture is a known risk, it is rare for patients to present with spontaneous rupture.

The authors report the case of a 32-year-old patient who required emergent neurosurgical intervention for spontaneous rupture of a left hemispheric arachnoid cyst.

Patients with ruptured arachnoid cysts can present with vague, nonspecific symptoms that may delay diagnosis. If not diagnosed and treated promptly, arachnoid cyst rupture can progress to a neurosurgical emergency as the subdural collection may cause extensive mass effect and even cerebral herniation.