Surgery for primary central nervous system lymphoma: Is it time for reevaluation?

Although they are the product of a retrospective unplanned subset analysis, the results of the correlative analysis of G-PCNSL-SG-1 may challenge long-held beliefs regarding the role of surgery for PCNSL. It is unlikely that a randomized trial will ever be performed, and for practical purposes it seems unlikely that the results of the recent analysis will be applicable to very many patients. First, relatively few patients with PCNSL will have tumors that are amenable to resection. Second, it is important to consider why surgical resection was attempted in G-PCNSL-SG-1, given longstanding recommendations not to resect PCNSL. It is likely that some patients had surgical debulking because of increased intracranial pressure and a risk of brain herniation. However, it is also reasonable to assume that the majority of patients had contrast-enhancing masses that, at the time of presentation, were thought to be primary brain tumors or metastases. Standard treatment in these situations is resection. In either case, it seems likely that few, if any, patients in this study had a known diagnosis of lymphoma before surgery. Instead, the diagnosis of lymphoma was probably made in retrospect. Patients rarely have surgery for 'lymphoma'; they have craniotomies for resection of a "brain tumor." It is possible that a stereotactic biopsy or a frozen section biopsy of a localized lesion could result in a situation where a neurosurgeon would need to make a decision whether or not to attempt a resection of a PCNSL. Otherwise, it is difficult to imagine many scenarios where a surgeon would need to make this decision. Thus, it is not clear that we really know much more now about surgery for PCNSL than we did almost 40 years ago when it was advised, "...if a localized tumor can be safely removed, this should be attempted."[45] In the absence of the highest quality data, at least it is good to know that in the modern era, patients with PCNSL are probably not harmed by judicious tumor resection.