An unusual extra-axial hypodense lesion mimicking a chronic subdural haematoma.

A 59-year-old man was found on the road with multiple injuries. CT scan showed a hypodense extra axial lesion in the left fronto-temporal region suggestive of chronic subdural haematoma. He was treated conservatively but did not improve. He underwent craniectomy after lesion was shown to be increasing in size, only solid tissue was seen which was not biopsied. Patient made good recovery after steroids were put on. He deteriorated again 6 weeks later and radiology showed the frontal lesion without involvement of the brain and with minimal enhancement and mass effect. He underwent biopsy decompression of the lesion with steroids, post-operatively he improved well, but deteriorated when the steroids were tapered. Histopathology report was Non-Hodgkin's lymphoma. No primary was found and the patient died during oncology treatment. This illustrates manifestation of primary dural lymphoma radiologically mimicking chronic subdural haematoma, another common disorder.