Hemispheric Chronic Subdural Hematoma Concealing Subdural Metastases: Terrible Surprise Behind Routine Emergency Department Consultation

The patient is a 79-year-old male, suffering from advanced metastatic prostate cancer, who developed a progressively worsening ideomotor slowing and was therefore referred to the emergency department of our institution. A plain axial computed tomography (CT) scan revealed a vast hemispheric subdural fluid collection, apparently a subdural hematoma. On closer inspection, and most of all, in hindsight, a tenuously isohyperdense signal irregularity at the frontal aspect of the fluid collection appears. Because of the declined general medical conditions and the paucity of the neurologic impairment, a high-dose, corticosteroid-based conservative strategy was performed. The total body CT scan for the routine oncologic follow-up of the prostate cancer scan fell at 20 days from the first CT of the emergency department. A second contrast-enhanced axial CT scan demonstrated the presence of 2 subdural metastases, presumably the initial pathogenesis of the subdural fluid collection.