B. Storch-Hagenlocher, M. Vogt-Schaden
With the development of imaging procedures, stereotactic biopsy, and new surgical techniques, general laboratory analysis has become less important in the diagnosis of brain tumors. In the case of primary brain tumors, serum laboratory tests are limited to a few hormonally active tumors. There are also no specific serum parameters for secondary brain tumors, and determination of tumor markers in serum is of limited importance as these markers only show nonspecific progression of the tumor. Determining tumor markers in CSF and calculating CSF/serum quotients in parallel may provide indications that a tumor is developing in the central nervous system. The special importance of CSF analysis lies in detecting malignant leptomeningeal spread, which is associated with varying frequency with primary brain tumors and with systemic malignant disease, and in differentiating these malignancies from inflammatory changes.