49 yrs old woman with diagnosis of DLBCL, diagnosed on core biopsy from retroperitoneal l/n. IH phenotype: Bcl2+ 100%, MUM1+ 80%, Bcl6+ 30%, Ki67+ 80%, CD10-.  
BM findings: INTERSTICIAL slightly clustered atypical "centro-immuno-blasts" ~5% with irregular vesiculated and lobulated nuclei in BM with some small T cell background. AT FIRST GLANCE (NASDE): Erythroid hyperplasia and arch abnormalities MDS like. Without knowing about lymphoma staging the subtle changes might be lost (photo IH only).  
 
PROPOSAL: minute spread of DLBCL in BM.  
SPECIAL QUEST: Minimum criteria sufficient for HIGH GRADE lymphoma diagnosis in BM.  
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