“…First, the definitions of PBML used in previous studies varied, partly due to its rarity, heterogeneous histology, and a lack of uniform pathological features 1, 2, 3, 4. Second, PBML often initially manifests as prolonged fever or fever of unknown origin (FUO), which is usually first examined by general practitioners 1, 2, 3, 4, 5, 7, 8, 9, 10. Hence, the diagnosis of PBML is often delayed, leading to a poor prognosis and a median overall survival (OS) of <18 months 1, 2, 3, 4.…”