Follicular lymphoma of the dura: case report.

Objective: We present an unusual dural-based follicular lymphoma with radiological and macroscopic features similar to a meningioma. The unusual location of this tumor and its distinction from meningioma, mucosa-associated lymphoid tissue-type marginal zone B-cell lymphoma of the dura, and intraparenchymal central nervous system lymphoma, dramatically alters the patient's postoperative treatment. The case illustrates the clinical, radiological, and histological relevance of this rare entity.

Clinical Presentation: A 41-year-old Caucasian man with chronic bifrontal headaches and a raised area over his left frontal cranium that persisted for 1 year presented to the emergency room with nausea and vomiting. His family reported that the patient demonstrated increased irritability and aggressive behavior. A computed tomographic scan revealed a large mass of the left frontal convexity with edema and mass effect. Magnetic resonance imaging scans showed a 5-cm homogeneously enhancing mass in the left posterior frontal lobe.

Intervention: Preoperatively, the patient underwent angiography and embolization of the tumor. The patient underwent gross total resection of tumor. The dural-based tumor invaded the cranium and scalp. Neuropathological findings were consistent with low-grade follicular lymphoma. The patient is currently undergoing radiation and chemotherapy.

Conclusion: The current case represents the first report of extensive intracranial dural involvement by a follicular lymphoma that shows a classic immunophenotype by immunohistochemistry and flow cytometry. The case illustrates the clinical and radiographic similarities between dural-based lymphoma and meningioma. Distinguishing dural-based follicular lymphoma from mucosa-associated lymphoid tissue-type lymphoma and from intraparenchymal primary central nervous system lymphomas, which are more often large cell lymphomas with more aggressive biological behavior, is essential for proper clinical management.