How is metastasis in CNS tumors?

➢ Most common cause of brain tumors in adults. ➢ Most often multiple (in 75% of cases). ➢ They originate from primary bronchopulmonary cancer in 30% of cases and mammary cancer in 25% of cases. ➢ When brain metastases are the first sign revealing a neoplastic process, the primary tumor is very often a bronchopulmonary cancer. ➢ More rarely, it can be a melanoma, a renal or digestive carcinoma. ➢ Metastases from a known primary cancer in progression (with histological evidence) are generally not biopsied.