QLTI-13. RETROSPECTIVE REVIEW OF THE DIAGNOSTIC YIELD OF CEREBROSPINAL FLUID (CSF) ANALYSIS IN DIAGNOSIS OF CENTRAL NERVOUS SYSTEM (CNS) LYMPHOMA IN A COMMUNITY NEURO ONCOLOGY CENTER

Abstract

Abstract Central nervous system (CNS) lymphoma can be a challenging disease to diagnose. Both primary and secondary CNS lymphoma often result in poor outcomes rendering early diagnosis and treatment essential. Traditionally, diagnostic modalities include surgery, cerebral spinal fluid (CSF) cytologic analysis, vitrectomy, and chorioretinal biopsy. Radiographic and clinical presentation can widely vary between patients, further enhancing diagnostic dilemma. We present a retrospective study from a community neuro oncology center analyzing the utility of CSF analysis in the diagnosis of CNS lymphoma. Between 2018-2022, 26 CNS lymphoma patients were identified of which 22 (85%) were primary CNS lymphoma patients. Median age of diagnosis was 68.5 years, and 21 (81%) of the patients were immunocompetent. 13 (50%) of the patients underwent CSF analysis, including cytology and flow cytometry), prior to biopsy and none (0%) yielded a positive diagnosis of CNS lymphoma. While mean CSF volume for cytology was slightly more than 3 cc of fluid, patients who had 5-10 cc of fluid sent for cytology also yielded a negative result for CNS lymphoma. For all patients, median duration from presentation of symptoms to surgery was 10.5 days. However, when divided between patients who proceeded straight to biopsy (CSFsecond) versus those who underwent CSF analysis prior to biopsy (CSFfirst), the duration from presentation of symptoms to surgery was 6 days versus 11 days, respectively. 10 patients in the CSFfirst group were not on steroids at the time of lumbar puncture whereas only 4 patients in the CSFsecond group were not on steroids at time of biopsy suggesting that steroid use did not seem to influence the yield of either diagnostic modalities. Our experience suggests that CSF analysis in community settings should be reserved only for staging and that surgical biopsy should be pursued as soon as the diagnosis of CNS lymphoma is considered.