P20.11.A DIAGNOSTIC DELAY OF PRIMARY CENTRAL NERVOUS SYSTEM LYMPHOMA (PCNSL) MAY BE CAUSED BY INFLAMMATORY DIFFERENTIAL DIAGNOSES

Le résumé fourni par la source

Abstract BACKGROUND PCNSL is a rare extranodal subtype of B-cell non-Hodgkin lymphoma initially located in the central nervous system. It can only be finally diagnosed with tissue sampling. Therefore, tumor biopsy and staging examinations beforehand can delay diagnosis. Consequently, PCNSL at histological diagnosis has often already evolved for a prolonged time. However, late therapy start may worsen treatment outcomes. A clearer delineation of PCNSL-specific clinical and imaging features that leads to an earlier diagnosis might accelerate start of therapy and improve prognosis. We here performed a retrospective analysis to construct a pathway that enhances this process. MATERIAL AND METHODS Clinical and imaging data of patients with histologically confirmed PCNSL diagnosed between 2012 and 2022 and hospitalized in the University Hospital Regensburg, was collected retrospectively from the local clinical management systems and tumor registry. Data included demographic, prognostic and clinical data incl. neurocognitive function (NCF), neuropathological and laboratory data, and magnetic resonance imaging (MRI). Descriptive analyses and univariate and multivariate analyses were performed. Survival data was calculated using the Kaplan Meier-method. RESULTS A retrospective cohort of 108 patients was investigated. Median time to diagnosis (TTD) was 40 (range, 6-1,100) days and median time to hospitalization (TTH) was 14 (range, 0-700) days. Median overall survival (OS) was 20 months (range, 0.5-125+). There was no significant correlation between TTD and OS (r= 0.001, p=0.990) nor between TTD and progression free survival (PFS) (r=0.031, p=0.756). However, TTH correlated significantly to TTD (r=0.429, p<0.001). Most common symptoms at incidence were cognitive decline (N=63, 59%) and psychiatric symptoms (N=41, 38%). Together, 6% of patients had positive McDonald criteria that would have defined autoimmune disease. MRI was the diagnostic technique with the greatest variation of differential diagnoses, including primary brain tumors in 44% of patients. Abnormal memory in NCF was detected as risk factor for decreased OS (HR=3.237, CI=1.111-9.434; p=0.023) and increased TTH (partial eta squared=0.279; p=0.024). CONCLUSION We conclude from our data that a delayed diagnosis of PCNSL cannot be verified as a causal factor for decreased OS or PFS. The relevance of a delayed diagnosis therefore may be restricted to certain subgroups who show a more dynamic disease. In relation to this hypothesis, the positive correlation of TTH to TTD suggests, that a subgroup of PCNSL may have a less dynamic course leading to a prolonged diagnostic period. Whereas symptoms like cognitive decline and psychiatric symptoms are typical for PCNSL, typical patterns in MRI do not occur and the rate of false negative diagnoses is high.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.