Diagnostic impact of preoperative corticosteroids in primary central nervous system lymphoma.

PURPOSE: High dose corticosteroids are an effective tool for rapidly alleviating neurologic symptoms caused by intracranial mass lesions. However, there is concern that preoperative corticosteroids limit the ability to obtain a definitive pathologic diagnosis, particularly if imaging features suggest primary central nervous system lymphoma (PCNSL). METHODS: To explore the impact of preoperative corticosteroids in newly diagnosed PCNSL patients, from 2009 to 2018 treated at our institution. RESULTS: We identified 54 patients; 18 had received corticosteroids prior to biopsy or resection. Only in one case did the patient have a prior non-diagnostic biopsy, requiring a second procedure. The cumulative doses of preoperative dexamethasone ranged from 4 mg to 120 mg (mean 32 mg, median 24 mg), given over 1-14 days (mean 2 days, median 1 day), and the majority had received corticosteroids for only 1-2 days. There was a trend for a larger diameter of lesional T1 contrast enhancement for patients who received steroids (39 mm vs. 34 mm, p = 0.11). In this series of cases with pathologically and clinically proven PCNSL, preoperative corticosteroids had been given in a third of cases, suggesting that they may be given for symptomatic relief without compromising pathologic diagnosis. CONCLUSIONS: Despite the commonly held tenet that preoperative corticosteroids can obscure the pathologic diagnosis in PCNSL, this is likely not the case in the majority of patients who receive a short course preoperatively. Obtaining a second stereotactic scan to confirm continued presence of the lesion prior to tissue sampling may also mitigate these concerns.