Symptomatic, expansive middle cranial fossa arachnoid cyst treated by a cysto-peritoneal shunt. Case report and evaluation of treatment options.

We report a symptomatic space-occupying arachnoid cyst in a 16-year-old boy. During the last two years, he was frequently absent from school because of headaches. Due to symptoms of nausea, fever and headache the patient was primarily referred to a surgical unit, where appendectomy was performed, revealing a normal appendix. Postoperatively, the patient complained of severe headache. Computed tomography (CT) of the head demonstrated a large left-sided middle cranial fossa arachnoid cyst. The patient was operated with insertion of a cysto-peritoneal shunt. A total regress of the clinical symptoms was seen at follow-up examination 3 months after shunting.