Primary Non Hodgkin’s Lymphoma of Cranial Dura Mater

Non-Hodgkin's lymphomas (NHL) rarely presents as a localized mass involving the dura. We present the case of a 55 year old lady with primary NHL of the dura. A 55 year old lady presented with seizures of 3 month duration. There was no neurologic defecit. Computed tomogram (CT) of brain showed a lobulated dural based well enhancing lesion in left frontoparietal and right frontal region extending into the anterior inter-hemisphere fissure (Figure1). The lesion showed peripheral calcification. Underlying bone was eroded and there was midline shift to right. Magnetic resonance imaging (MRI) showed a sheet like extraaxial lesion of variable thickness involving the convexity suba-rachnoid space, enveloping the majority of left cerebral hemisphere. It extended into the subarachnoid space of interhemispheric fissure. It appeared hypointense on T1W1, isointense on T2W1 and hyperintense on flair sequence (Figure 2). Patient underwent left frontoparietal craniotomy and tumor decompression. She presented to us following the surgery. On examination, she had palpable bilateral cer-vical lymphnodes. Her Hematology was normal, and lactate dehydrogenase was 521 IU. Histopathologic examination of the resected specimen showed infiltration by lymphoid nodules composed of small cleaved cells intermixed with large cells. Tumor cells were positive for Leucocyte common antigen (LCA), CD20 and negative for CD138. It was diagnosed as malignant lymphoma diffuse large B cell type. Bone marrow and other staging work up were normal. She received chemotherapy with rituximab, cyclophos-phamide, vincristine, doxorubicin and prednisolone (RCHOP) for 6 courses. Local irradiation was planned, however, she refused the same. She remains in complete remission at 45 months. Primary dural lymphoma is a rare disease with more indolent clinical behavior compared to primary central nervous system lymphoma. It represents less than 1% of all brain lymphomas. The majority of the reported cases are indolent marginal zone lymphomas, only very few cases of diffuse large B-cell lymphoma of the cranial dura has been reported. The symptoms depends on the location of the tumor and includes headaches , seizures, focal sensory or motor deficits, visual disturbances, nausea, vomiting, and ataxia. Single or multiple dural-based extraaxial lesions that diffusely enhance after gadolinium injection are the typical ra-diologic feature on MRI. 3 Figure 1. Coronal post contrast CT scan showing lobulated dural based well enhancing lesion in left fron-toparietal region. Figure 2. MRI showing the extraaxial lesion involving the convexity.