Walsh & Hoyt: Bone Metastases

The close application of the dura mater to the cranial bones facilitates direct spread of malignancies. It is thus not unusual to find flat, irregular plaques of metastatic tumor on the inner surface of this membrane adjacent to an area of bone invasion by tumor. When the dura is extensively infiltrated by tumor, there may be effusion of blood and formation of a false membrane on the inner aspect of the dura. The most frequent sources of bone metastases are carcinomas of the lung, prostate, breast, and gastrointestinal tract.