Primary Dural Lymphoma Case Report: A Distinct Subtype of Primary Central Nervous System Lymphoma

Primary CNS lymphoma (PCNSL) is an aggressive form of extranodal non-Hodgkin lymphoma that arises in the brain parenchyma, eyes, meninges, or spinal cord in the absence of systemic disease. Primary dural lymphoma (PDL) arises from the dura mater of the brain. It differs biologically from other CNS lymphomas. It is usually a low-grade B-cell marginal zone lymphoma (MZL), whereas other types of PCNSL are usually high-grade large B-cell lymphoma. This specific pathological subtype has important therapeutic and prognostic implications, making PDL a distinct subtype of PCNSL. Herein, we report a case of PDL in an African American patient who presented with chronic headaches. MRI of the brain showed a dural-based homogeneously enhancing extra-axial mass along the left hemisphere and was contained within the anterior and parietal dural matter. The malignant cells stained diffusely positive for CD19, CD20, and CD22 but negative for CD5, CD10, Cyclin D1, and CD56. Ki67 was 10–20%, consistent with extranodal marginal zone lymphoma. Given the location and pathology, the patient was diagnosed with PDL. She was started on treatment with bendamustine and rituximab. Due to Marginal Zone Lymphoma’s indolent nature, location outside the blood brain barrier, and known efficacy of bendamustine-rituximab, we decided to treat our patient with Bendamustine-Rituxumab. She completed six cycles, and post-therapy MRI brain showed complete remission. Our case adds to the sparse literature about primary dural lymphoma.