Increased capillary permeability in tumors within the brain causes a breakdown of the blood-brain barrier1: and in tumors within the subarachnoid space, a breakdown of the blood-cerebrospinal fluid barrier.2 It seemed likely, therefore, that this capillary leakage could explain the accumulation of fluid in a cystic brain tumor. To investigate this possibility, protein fractionation studies were made on the fluids and sera of patients with cystic brain tumors.
Materials and Methods
Twenty-four patients, 12 males and 12 females, ranging in age from 7 to 67 years, who had cystic brain tumors provided the materials for study. Twenty-one had primary intracranial tumors. Three had metastatic tumors. Cyst fluid and blood were collected simultaneously at the time of operation. Total protein was determined by the biuret method3 or by the micro-Kjeldahl technique.4 Electrophoresis was carried out by Longsworth's5 modification of the Tiselius technique, using barbiturate buffer pH