Arachnoid interamigdal cyst of the posterior fossa in an adult female

Abstract

Introduction: Arachnoid cysts are benign extracerebral collections of cerebrospinal fluid; a very low incidence has been described as part of all intracranial lesions (about 1%). They appear in the different anatomical areas of the neuroaxis where arachnoids exist; the majority are supratentorial and in the middle fossa (50-60%). In general, less than 50% of cases present manifestations that merit surgical treatment. Case report: A 55-year-old female underwent surgery due to torpid evolution as a result of an arachnoid cyst in the posterior fossa. She started suffering from episodes of pulsatile headache 2 years ago without irradiation accompanied by occasional vertigo that was attenuated with conventional analgesia. In the past week, the pain was exacerbated, as was the vertigo, intolerance to the oral route, and generalized weakness. A scheduled surgical intervention was decided on, and a histopathological study reported characteristics compatible with an arachnoid cyst. Discussion: Arachnoid cysts are an uncommon pathology that sometimes requires surgical intervention. In the case presented, the incipient clinic manifestations showed that the patient had an abrupt progression in her intensity, perhaps due to an increase in size, conditioning the increasing headache, and added symptoms. This culminated in her assessment and surgical intervention due to the important compression of the brain stem. It was considered a successful procedure due to the disappearance of the symptoms and the return to her activities. Conclusions: Surgical intervention for posterior fossa arachnoid cyst is an excellent treatment when the symptoms do not improve after having maintained an expectant conduct through conservative management.