Primary extranodal marginal zone mucosa-associated lymphoid tissue-type B-cell lymphoma involving the dura: A case report.

Background: Primary extranodal marginal zone mucosa-associated lymphoid tissue-type B-cell lymphoma (EMZMBCL), which presents as a dural mass, is a rare intracranial tumor that mimics a subdural hematoma or meningioma. Case Description: A 49-year-old woman presented to our hospital with transient right upper limb paresis, dysarthria for 10 min, and ongoing right upper-limb numbness. Computed tomography (CT) of the head revealed extra-axial lesions in the left frontal and parietal lobes. Based on the initial CT findings in the emergency room, an acute subdural hematoma was suspected. However, meningiomas and other intracranial tumors were also listed as differential diagnoses because there was no history of head trauma or coagulation abnormalities on blood examination, and further imaging studies were performed. Imaging findings suggested a subdural neoplastic lesion. A partial resection was performed for the lesion. Based on histopathological and immunohistochemical examinations, the patient was diagnosed with EMZMBCL. Whole-brain and intensity-modulated radiation therapies were administered as adjuvant therapies. The patient was discharged without neurological deficits. Conclusion: EMZMBCL is a rare disease that should be considered in the differential diagnosis of subdural lesions, especially when there is no history of trauma or abnormalities in the coagulation system. The patient had a favorable outcome after selecting radiotherapy as the adjuvant therapy.