In Reply With interest we read the letter to the editor by Zhang and Wu. As described, our patient presented with recurrent episodes of neurologic deficit, improving after administration of steroids compatible with chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids.1 Eventually, the patient was diagnosed as having lymphomatoid granulomatosis resulting in a B-cell lymphoma. This central nervous system B-cell lymphoma was suggested by magnetic resonance imaging characteristics and biopsy prior to the patient’s death and was confirmed by postmortem autopsy. Microscopic tissue analysis showed a large pontine area (markedly enhancing on brain magnetic resonance imaging) with necrosis and a focal thalamus lesion with large atypical lymphocytes and perivascular infiltrates, including atypical lymphocytes, small lymphocytes, and macrophages, compatible with a B-cell lymphoma. Immunohistochemistry findings indicated large quantities of atypical CD-20–positive cells with some T cells. About 10% to 20% of tumor cells were Epstein-Barr virus–encoded RNA positive. Thus, the final diagnosis of B-cell lymphoma could be confirmed post mortem. We agree that magnetic resonance spectroscopy might be helpful in differentiating inflammatory and neoplastic lesions. However, in the context of chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids, there is limited experience using this method, which does not allow drawing strong conclusions for diagnostic purposes.
De Graaff HJ, Wattjes MP, Rozemuller AJ, Petzold A, Killestein J. Chronic Lymphocytic Inflammation With Pontine Perivascular Enhancement Responsive to Steroids and Fatal B-Cell Lymphoma—Reply. JAMA Neurol. 2013;70(11):1459-1460. doi:10.1001/jamaneurol.2013.4757