Alphafetoprotein and human chorionic gonadotropin determination in cerebrospinal fluid

Abstract

The CSF and serum of 6 patients with histologically verified intracranial germ cell tumors were assayed serially for presence of .alpha.-fetoprotein (AFP) and the .beta. subunit of human chorionic gonadotropin (HCG). Two patients had embryonal carcinomas, 2 had choriocarcinomas and 2 had dysgerminomas. The marker profile for a given tumor in CSF or serum correlated with the histological diagnosis; i.e., embryonal carcinoma produced AFP and HCG, choriocarcinoma produced HCG and dysgerminoma produced no markers. Marker levels in serum and CSF declined with therapy and rose usually prior to overt clinical symptom development if the patient''s tumor recurred. A CSF-to-serum gradient of marker levels was present in 3 of 4 patients, and the serum levels were often normal when CSF values were elevated. Ventricular marker levels were lower than lumbar levels in 2 of 2 patients. The assay of these biological markers is a sensitive indicator of therapy success and presence of a CSF-to-serum gradient suggests that the neoplasm portion rests within the CNS. A histological diagnosis can be inferred without surgery necessity in appropriate clinical contexts.