The blood-brain barrier and response of C.N.S. metastases to chemotherapy.

A case demonstrating a differential effect of chemotherapy on a pineal metastasis and parenchymal cerebral metastases is described. At presentation, extensive metastatic small cell carcinoma of the lung was present and CT scanning showed an apparently solitary metastasis in the pineal. The clinical course and serial CT scans showed significant improvement of the pineal tumor and simultaneous development of multiple intra-cerebral metastases. This case confirms that the pineal gland is excluded from the blood-brain barrier, and indicates the clinical importance of the effect of the blood-brain barrier in the responsiveness of CNS metastases to chemotherapy.