The clinical symptoms and signs of four patients with arachnoid cysts in the posterior fossa are discussed. In three patients, the cyst was in the internal auditory canal; one patient had an acoustic neuroma and two large cysts in the cerebellum. Whereas the conventional diagnostic tests for acoustic neuroma cannot differentiate between neuromas and arachnoid cysts, the newer thin section body scanners can show a lesion with no enhancement in the case of the cyst. Surgical approaches for removal of this lesion must take into consideration the preservation of hearing in the involved ear.
BannaM: Arachnoid cysts in the hypophyseal area. Clin Radiol25: 323–326, 1974.
3.
BrackmannDEBartelsLJ: Rare tumors of the cerebellopontine angle. Read before the 1979 Annual Meeting of the American Academy of Otolaryngology, Dallas, Oct 10, 1979.
4.
DyckPGruskinP: Supratentorial cysts in adults. Arch Neurol34: 276–279, 1977.
5.
SumnerTEBentonCMarshakG: Arachnoid cyst of the internal auditory canal producing facial paralysis in a three-year old child. Radiology114: 425–426, 1975.
6.
BengocheaFGBlancoFL: Arachnoidal cysts of the cerebellopontine angle. J Neurosurg12: 66–71, 1955.
7.
WilnerHIKashefR: Unilateral arachnoid cysts and adhesions involving the eighth nerve. Am J Roentgenol115: 126–132, 1972.
8.
AubryMOmbredanneM: Etude oto-neurologique of chirurgicale du vertige. Indications et resultats de la chirurgie intracranienne du nerf auditif. Paris, Masson & Cie243: 100–122, 1937.
