Primary dural lymphoma mimicking a subdural hematoma.

Intracranial marginal zone B-cell lymphoma presenting as a dural-based mass is rare. A 45-year-old woman who had generalized tonic-clonic seizures and speech disturbance for 6 months was referred to our hospital. Radiology suggested a subdural hematoma (SDH). No improvement in the radiological findings or symptoms occurred with conservative follow-up. Therefore, she underwent a craniotomy for drainage of the suspected SDH. Intraoperatively, dural plaque-like thickening was observed, with no SDH, and a biopsy was performed. After histopathological and immunohistochemical studies, a mucosa-associated lymphoid tissue (MALT) lymphoma was diagnosed. The patient underwent radiotherapy with no postoperative complications or recurrence. Early diagnosis and treatment of primary dural lymphoma is important. Histopathological evaluation is necessary for diagnosis. MRI cannot reliably differentiate between SDH and some dural lesions that present as diffuse infiltration. Therefore, these differential diagnoses should be considered.