[Arachnoid cyst of the quadrigeminal cistern].

Arachnoid cyst located near the quadrigeminal cistern has been reported as paracollicular arachnoid cyst, arachnoid cyst of the quadrigeminal cistern, paramesencephalic arachnoid cyst, arachnoid cyst posterior to the third ventricle, cyst of the cisterna ambiens. The purpose of this paper is to present the clinical pictures, diagnostic studies and treatment of 5 cases of the arachnoid cyst of the quadrigeminal cistern. (1) The clinical symptoms and signs result from increased intracranial pressure without lateralizing signs (mid-line syndrome) due to hydrocephalus, precocious puberty and supra-collicular sign due to direct compression of the adjacent structures. (2) Endocrinological study of the pituitary gland shows no abnormal findings, but the patients with precocious puberty shows adult type response in LH and FSH. (3) Metrizamide CT cisternography could be considered as a safe and reliable neurological procedures in evaluating the communication between the cyst and the subarachnoid space as well as CSF dynamics, and subarachnoid space. (4) Patients were treated with ventriculoperitoneal shunt, followed by craniotomy and resection of the cyst wall with good results.