In Reply With great interest we read the letter by Taieb et al further discussing whether chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS) should be considered a prelymphoma state or a new inflammatory disease.
In our reported case, the histologic lymphomatoid granulomatosis characteristics comprising angiocentric/angiodestructive lymphoreticular proliferation have not been described as such for the first brain biopsy.1,2 We agree that a primary central nervous system lymphoma (PCNSL) is a possible differential diagnosis. In addition to the proposed in vitro hybridization, it may be possible to investigate this hypothesis by testing for light chain–restricted monoclonal expansion of the B-cell population. Unfortunately, we were not able to do so because no material was available in our case. Accepting the differential diagnosis, it should be stressed that our case fulfilled the original diagnostic criteria for CLIPPERS.3
De Graaff HJ, Wattjes MP, Rozemuller AJ, Petzold A, Killestein J. Should CLIPPERS Be Considered a Prelymphoma State or a New Inflammatory Disease?—Reply. JAMA Neurol. 2013;70(9):1201. doi:10.1001/jamaneurol.2013.3855