Elevation of carcinoembryonic antigen in cerebrospinal fluid among patients with meningeal carcinomatosis.

The concentration of carcinoembryonic antigen (CEA) in cerebrospinal fluid (CSF) was determined by using an enzyme immunoassay for 204 patients with various nonneoplastic neurologic disorders, 8 patients with systemic infectious diseases, 19 patients with systemic neoplastic diseases without involvement of the nervous system, and 35 patients with neoplastic neurologic disorders. The highest CEA level in CSF among patients without neoplastic neurologic disorders was 0.6 ng/ml. Of 35 patients with neoplastic neurologic disorders, 10 had CEA levels in CSF that exceeded 0.6 ng/ml, the highest level being 70.5 ng/ml. All 10 patients had carcinomas. Among 14 patients with neoplastic meningitis, 5 of 8 patients with meningeal carcinomatosis had elevated CEA concentrations. Although the efficacy of the assay for CEA in CSF must be compared with that of other laboratory tests such as cytologic examination and the assay for beta-glucuronidase--and any potentially false-positive results should be ruled out by determination of the serum CEA level--the CEA concentration in CSF can be used as an adjunctive diagnostic procedure for detection of meningeal carcinomatosis.