3RD VENTRICLE COLLOID CYSTS - A CONSECUTIVE 12-YEAR SERIES

A continuous follow-up review of colloid cysts including aspects of na tural history and evaluation of treatment options is necessary to opti mize individual treatment. Thirty-seven consecutive patients with coll oid cyst of the third ventricle seen at Karolinska Hospital between 19 84 and 1995 were reviewed. Five patients were admitted in a comatose s tate, and two died despite emergency ventriculostomy. Three had recurr ent cysts following previous aspiration procedure. During the study pe riod, patients underwent a total of 10 ventriculostomies, 10 aspiratio ns, 26 microsurgical operations, and two shunt operations. Twenty-four of 26 microsurgical operations were transcallosal and two were transc ortical. Twenty-four operations (22 transcallosal and two transfrontal approaches) without permanent morbidity were performed by four surgeo ns. Transient memory deficit from forniceal traction was noted in 26%. The remaining two transcallosal operations, which led to permanent mo rbidity or mortality, were performed by two different surgeons. Aspira tion of cysts performed by four different surgeons carried a 40% risk of transient memory deficit (10% permanent) and an 80% recurrence rate . One patient was found to be cured on radiological studies obtained a t the 5-year follow-up review. Seven cysts were followed by means of r adiological studies with no treatment for 6 to 37 months. Five of thes e cysts grew, indicating that younger patients with colloid cysts will probably need surgical treatment. The main causes of unfavorable resu lts were: 1) failure to investigate symptoms that proved fatal; 2) sub total resection; and 3) surgical complications. Transcallosal microsur gery produced excellent results when performed by experienced surgeons . A colloid cyst of the foramen of Monro is a disease that should be d etected before permanent neurological damage has occurred. Permanent m orbidity or mortality should not be accepted in modern series of third ventricle colloid cysts.