Intraspinal arachnoid cysts.

Eight cases of intraspinal arachnoid cysts are described. The clinical, radiological, intraoperative and histological findings are presented and compared with similar reports in the literature. Opinions in the literature concerning the origin of arachnoid cysts are discussed, and compared with our own case reports. A traumatic or inflammatory origin of the arachnoid cysts is denied if accompanying histological changes are lacking. In such cases the arachnoid cysts are to be viewed as congenital malformations.