Repeated Short-Term Recurrence of Chronic Subdural Hematoma Associated with Metastasis to Hematoma Capsule Originating from Extracranial Malignant Tumor

To the best of our knowledge, this is the first report of metastasis to a hematoma capsule originating from an extracranial malignant tumor. The clinical course in the present case suggests metastasis of extracranial malignant tumor to the CSDH capsule as an extremely rare cause of recurrence.