Spinal fluid lysozyme in the diagnosis of central nervous system tumours.

C.S.F. lysozyme concentrations were determined in 24 normal subjects and 14 patients with a variety of neurologic diseases. We found absent or very low activity (below 0-5 mg/ml, in 4 out of 24) in normal individuals. Patients with tumours and other neurological diseases had high lysozyme activity in C.S.F. Our findings suggest that lysozyme is not an accurate indicator of the presence of neoplastic disease as suggested by other investigators.