Neuroinflammation Preceding and Accompanying Primary Central Nervous System Lymphoma: Case Study and Literature Review

BACKGROUND: Primary central nervous system lymphoma (PCNSL) is an aggressive lymphoma confined to the CNS. Although the pathogenesis of PCNSL in immunocompetent individuals remains unclear, there have been several case studies demonstrating the sentinel inflammatory lesions months before the manifestation of PCNSL. However, the pathologic relationship between the inflammatory lesions and subsequent PCNSL is still unknown. CASE DESCRIPTION: We present the case of a 44-year-old immunocompetent woman who developed several cerebral and cerebellar lesions on magnetic resonance imaging (MRI). A partial resection of the cerebellar contrast-enhancing lesion showed active inflammation with large destructive process but no evidence of B-cell lymphoma. Her disease was in a relapsing-remitting course for 28 months and progressed with new MRI findings of more contrast-enhancing lesions. She died at 33 months after the initial presentation. Postmortem examination revealed B-cell PCNSL with extensive involvement but sparing a few brain regions, including the previous resection site, with only an inflammatory destructive process. CONCLUSIONS: PCNSL may be preceded and accompanied by an inflammatory process that is pathologically distinct from PCNSL. Our case study, in combination with a review of previously published similar cases, supports the hypothesis that the sentinel inflammatory lesions may be the first immune response against PCNSL.