Common primary sites of metastasis to the brain are-

METASTATIC TUMOURS Approximately a quaer of intracranial tumors are metastatic tumors. Most common primary tumors metastasizing to the brain are:- carcinomas of the lung, breast, skin (malignant melanoma), kidney and the gastrointestinal tract and choriocarcinoma. Infiltration from lymphoma and leukemias may also occur. MORPHOLOGIC FEATURES. Grossly, the metastatic deposits in the brain are usually multiple, sharply-defined masses at the junction of grey and white matter. A less frequent pattern is carcinomatous meningitis or meningeal carcinomatosis in which there is the presence of carcinomatous nodules on the surface of the brain and spinal cord, paicularly encountered in carcinomas of the lung and breast. Histologically, metastatic tumors in the brain recapitulate the appearance of the primary tumor of origin with a sharp line of demarcation from adjoining brain tissue. It is usually surrounded by a zone of edema. Ref: TEXTBOOK OF PATHOLOGY 6th EDITION - HARSH MOHAN PAGE NO:891