ABSTRACT
INTRODUCTION Primary tumors of the central nervous system need to be distinguished from metastatic lesions. Although primary brain tumors are relatively rare in adults, with a yearly incidence of approximately 10/100,000 representing only 2% of all malignancies, brain metastases (secondary brain tumors) are more common and present in almost one out of four patients with advanced stage cancer and in onefourth of patients who die from cancer. The most common primary tumors are lung, breast carcinoma, and melanoma. An increasing incidence of both primary and secondary brain tumors since the 1970s has been suggested. This likely reflects greater access to imaging and improved neuroimaging techniques as well as better treatments and longer survival of cancer patients in general.
