How big a meningioma grows in a year varies from person to person and there is no exact number. However, most meningiomas are slow growing and usually do not grow more than 2 to 4 millimeters in 1 year. Meningiomas are common intracranial tumors, most of them are benign and slow-growing, and most of the patients’ tumors do not grow more than 2~4 mm in 1 year, and in many cases, there is no obvious change for many years. However, a very small number of mesenchymal and malignant meningiomas will grow significantly faster than benign meningiomas. The progression of a meningioma is usually determined by reviewing a CT or MRI of the skull. In addition, the size of the meningioma is not the main basis for treatment; what is more important is the location of the tumor, whether or not it is compressing the surrounding tissues, and whether or not there are any obvious symptoms. Patients with this disease should be followed up regularly in the hospital to determine the treatment based on the opinion of the brain surgeon.