What are the most common metastatic tumours of the brain?

Metastasis is part and parcel of the definition of a cancer and so any malignant tumour may metastasise to the brain. However, certain types are more likely than others.

The cancer that has the highest rate of brain metastasis is the malignant melanoma - around two thirds of these tumours end up in your lodged in your brain.

However, it doesn't follow that the msot frequently found type of brain metastasis is therefore a melanoma - melanomas aren't the commonest cancer type. Rather, it turns out that the lung (bronchus) and the breast are the commonest primaries for brain metastases. Only around 25% of these tumours send offshoots to the brain, but seeing as they are much more common than melanomas, they account for the majority of mets there.

Metastases usually lodge around the border between the white and grey matter, and are usually found in the cerebral hemispheres, rather than the cerebellum.

Source: Neurology and Neurosurgery Illustrated (Lindsay, Bone; 4th edn.)