Cylindromas of the base of the skull. Report of four cases.

Cylindromas are rarely encountered in the neurosurgical field. Four cases of this rare tumor are presented. Conventional and computerized tomography scanning were most useful in establishing the diagnosis; angiography did not provide any further information. Because these tumors are well demarcated from surrounding structures, even in cases of recurrence, surgery is the treatment of choice. Radiation therapy is useful in the postoperative management. Long survival times with multiple recurrences are the rule.