Prostate dural metastasis presenting as chronic subdural hematoma. A case report and review of the literature

BACKGROUND: Malignant disease metastasising to the cranial dura is rare. Dural metastases manifesting as a subdural fluid collection and presenting as a chronic subdural hematoma is an uncommon entity with unknown pathophysiology. CASE DESCRIPTION: We present a patient with known prostate cancer metastasising to the cranial dura masquerading as a chronic subdural hematoma. The patient presented with bilateral subdural collections manifesting with confusion and dysphasia. Initial drainage of the larger, symptomatic left side improved only temporarily patient's symptoms. A second drainage of the collection was performed on the same side 5 days later and dural biopsies taken during the same procedure revealed prostate metastases. The patient improved slowly and was discharged to a hospice for palliative care management. CONCLUSIONS: Prostate dural metastases should be suspected in patients with known prostate cancer presenting with a subdural collection in the absence of cranial trauma. If decision to drain the subdural collection is taken, then biopsies can be taken the same time as they can pose a diagnostic challenge.