Carcinoembryonic antigen in patients with intracranial tumors.

Carcinoembryonic antigen (CEA) in plasma, cerebrospinal fluid (CSF), and tumor cyst fluid obtained from patients with a variety of intracranial tumors was determined by radioimmunoassay Slightly elevated levels of plasma CEA, ranging from 2.6 to 3.8 ng/ml, were noted in six (4%) of 161 patients with primary brain tumors: in three gliomas, two pineal tumors, and one acoustic neurinoma, respectively. On the other hand, 17 (37%) of 46 patients with metastatic brain tumors showed a definite elevation, and most of them had values higher than 5.0 ng/ml. Of 37 patients with primary brain tumors, only one with a pineal germinoma showed a significant elevation of CEA in CSF, whereas eight (44%) of 18 patients with metastatic brain tumors showed high values of CEA in CSF. All six patients with leptomeningeal carcinomatosis showed elevated CEA in CSF. Levels of CEA in tumor cyst fluid were determined in 17 patients with intracranial tumors, including 12 gliomas, two craniopharyngiomas, two metastatic tumors, and one meningioma; elevation of CEA in tumor fluid was noted in two craniopharyngiomas and one metastatic tumor. Sequential determination of CEA of plasma or CSF revealed that the CEA levels were well correlated with the activity of brain tumors. Consequently, the determination of CEA in plasma or CSF is valuable for the differential diagnosis between primary and metastatic brain tumors and for the management of CEA-producing tumors.