A 48-year-old man presented with sudden-onset headache and vomiting for 6 h and altered sensorium for 2 h. He was febrile with tachycardia, neck rigidity and positive Kernig’s sign. Cerebrospinal fluid examination showed neutrophilic pleocytosis, raised protein and low glucose. Non-contrast CT revealed a large, well-circumscribed hypodense mass measuring 5×3 cm involving the right frontobasal area with subtle peripheral calcification. The mean attenuation value of the hypodense area measured 87 Hounsfield units. MRI was performed to characterise the mass further (figs 1, 2).