Cerebrospinal fluid test cannot exclude tumor. Patients with brain tumors or tumors from other parts of the body that have metastasized to the brain may find tumor cells or elevated globulin in cerebrospinal fluid examination, which can assist in the diagnosis of brain tumors. However, the absence of abnormalities in cerebrospinal fluid routine, biochemistry or exfoliative cytology in cerebrospinal fluid examination does not mean that the patient can rule out the occurrence of brain tumor. Usually, the most direct way to rule out cranial tumors is to conduct CT and MRI scanning and enhancement examinations. Through these examinations, the location and size of the brain tumor can be clearly detected, and treatment methods can be considered according to different types of tumors. If the cerebrospinal fluid examination fails to confirm the diagnosis, further examination should be done, and the patient should actively consult the doctor to avoid delaying the condition.