We found it very interesting to read the report on “Sarcoidosis-lymphoma Syndrome”, by Brandy-García et al., recently published in Reumatología Clínica,1 in which the authors review the history of the first description and subsequent communications in Spain, and contribute to our knowledge of this condition. In their study, they point out the difficulty in distinguishing between the two diseases in the differential diagnosis, and particularly establish the complexity of the diagnosis of neurosarcoidosis, given the lack of specificity of the imaging studies, as well as the difficulty in accomplishing a pathological study.

The authors were able to summarize and analyze the most important and controversial aspects that the physicians responsible for these patients need to confront day after day; however, although we share their conclusions, we believe that some consideration should be given to the diagnostic tests. We wish to point out that when they mention normal lumbar puncture and cytometry in which a T lymphoid population was recognized, it is not clear which sample corresponded to the cytometric study.

Especially, in this case, it must be acknowledged that, given the absence of a histological study, it is evidently difficult to identify the definitive diagnosis on the basis only of the clinical signs and the imaging studies. However, the unavailability of a histological diagnosis should not be a barrier that delays the diagnosis and treatment in these cases.

For this reason, we consider it relevant to point out the need for flow cytometry of the cerebrospinal fluid,2,3 whenever it is not contraindicated, in patients with a history of sarcoidosis and in whom the involvement of the central nervous system is suspected, to obtain confirmatory and more accurate data on the correct diagnosis.

We agree with the authors that there is a lack of scientific evidence on this subject. Therefore, we would like to thank them for publishing their notable contribution to help us to make progress in the diagnosis of this disorder.