[A case of subdural effusion secondary to dural metastasis of prostatic cancer: case report].

The authors reported a case of subdural effusion secondary to dural metastasis of prostatic cancer. A 61-year-old man was referred for headache, vomiting and gait disturbance. He had undergone hormonal therapy for prostatic cancer. He showed a mild left hemiparesis and anemia without bleeding. CT-scan disclosed a multilobular crescent shaped low density area in the right hemisphere. Under the diagnosis of chronic subdural hematoma, burr hole irrigation therapy was performed. Xanthochromic fluid was evacuated from the subdural space, in which no tumor cells were shown to exist. CT-scan on the 21st day disclosed a low density area, which was diagnosed as recurrent chronic subdural effusion. Therefore, craniotomy was performed to evacuate the subdural fluid and to explore the dura mater. Removal of the red hemorrhagic tumor at the dura mater and the fluid was performed. The patient died of heart failure in the 16th month despite complete recovery after the second operation. Histopathological examination of the tumor revealed adenocarcinoma at the outer part of the dura mater and the adjacent skull bone, where capillaries were embolized with tumor cells. However, no tumor cells were found in the subdural fluid. The authors could find in the literature 30 cases of subdural hematoma or effusion secondary to dural metastasis of carcinoma. The pathogenesis of the subdural hematoma in this case might be due to circulatory disturbance at the dura mater brought about by the invasion of the tumor or tumor cells emboli in the capillaries.