RESUMO
Perineural cysts are common lesions of the sacral spine. They have rarely been reported in a presacral location, leading to their misdiagnosis as a gynecological lesion. The authors report the second such case, in a patient undergoing fenestration of what was presumed to be a benign pelvic cyst, and the resultant high-flow CSF leak that occurred. They describe the clinical presentation and manifestations of intracranial hypotension, as well as the pertinent investigations. They also review the literature for the best management options for this condition. Although they are uncommon, large perineural cysts should be included in the differential diagnosis when examining patients with a pelvic lesion. Appropriate imaging investigations should be performed to rule out a perineural cyst. The CSF leak that occurs from iatrogenic cyst fenestration may not respond to traditional first-line treatments for intracranial hypotension and may require early surgical intervention. The authors would recommend neurosurgical involvement prior to definitive treatment.