73 yrs old male with known "lymphocytosis" and gastric tumor- biopsied now.  
HISTO: Diffuse "immunoblastic" discohessive infiltration of large cells in the lamina propria.  
IH (scarse): ONLY POSITIVES: CD68+; CD10+; CyclinD+; CMYC+; CD138+ (focal); Bcl2+ faint focal; INI1+; CD99+ (faint); Synaptophysin+ (dirty/artefacts?); Ki67 HIGH 85%.  
 
Other CARCINOMA SARCOMA LYMPHOMA MELANOMA markers complettelly absent:  
PanCK/Cam5.2/S100/MelanA/PLAP/EMA/BerEp4(-); MPO/CD56(-); Ig kappa/lambda(-);Pax5/CD20/CD3/CD30/CD79a/LCA/CD43(-); CD34/TdT/CD117/HLADR/CD123(-); EBER(-); CD1a/Langerin/Lysozyme/CD4(-); Desmin/Myogenin/PLAP(-).  
 
Molecs: NON CLONAL; BRAF(-).  
 
PROPOSALS/QUESTIONS:  
 
1. B plasmablastic lymphoma (CyclinD1+ CD138+ EBER(-) Ig kappa/lambda(-) Mum1(-))- probably transformed from possible B CLL/SLL;  
2. Myeloid sarcoma; CD68+ CD10+ CD34/TdT/CD117/Bcl/HLA DR(-);  
3. Histiocytic lymphoma: CD68+ S100/CD1a/Lysozyme/CD43(-)...  
 
Thankyoubeeingsoclose.