Primary cerebral venous thrombosis in patients with cancer--a rarely diagnosed paraneoplastic syndrome. Report of three cases and review of the literature.

Idiopathic thrombosis of the cerebral venous structures is a rare complication of malignancy. The clinical, radiologic, pathologic, and laboratory findings in the 15 previously reported cases are reviewed, and three additional cases are reported. The clinical syndrome that develops in such patients is similar to that seen in other patients with cerebral venous or sinus thrombosis. However, the diagnosis is often not made clinically because cerebral involvement by neoplastic disease provides a more common and readily acceptable explantation of the observed phenomena. If venous thrombosis involving the brain is suspected, angiography provides the only certain method of diagnosis. The relationship of this thrombotic process to a cancer-associated hypercoagulable state is discussed.