Acute aggravation of subdural effusion associated with pachymeningitis carcinomatosa: case report.

The authors present a case of acute aggravation of subdural effusion associated with pachymeningitis carcinomatosa. Microscopic examination of a surgical specimen revealed diffuse involvement of the dura mater by a metastatic adenocarcinoma in which the tumor cells invaded venules located in the areolar layer in particular. The rapid increase in capillary transmural pressure resulted in extravasation of plasma components, causing an increase in subdural effusion.