Infratentorial retrocerebellar cysts.

Clinical analyses of ten cases of infratentorial retrocerebellar cysts were performed in order to define specific signs or symptoms and thus improve the preoperative diagnosis. There were not symptoms or signs specific for the cysts. When a tumor in the posterior fossa is suspected by ventriculography, vertebral angiography or pneumoencephalography should be performed to exclude the possibility of a cyst, particularly in patients under 20 years of age. Care should also be taken to look for supratentorial cysts, since multiple cysts are found occassionally. It is necessary to evaluate the therapeutic program for each case, depending on the relationship between the cyst and the subarachnoid space and ventricular system. Postoperative follow-up is important, especially in cases in which only excision of the cyst is performed.