38 yrs old male with resected CNS tumor (headaches and CT diagnostics). EXTERNAL material (IH quality suboptimal).  
HISTO: on the slides: dense, predominatelly T small-medium lymhoid angiocentric infiltrate with ovoid and irregular/atypical nuclei. Perifocal necrosis with histiocytic reaction and haemophagocytosis signs. Plasmacytic admixture.  
IH: CD3(+/+++)100%; CD20(-); CD2(+++)100%; CD5(++)80%; CD7 (-)(?)(about 30% of population +: reactive?); CD4(-); CD8(+++)100%; Granzym B(++/+++)100%; TIA1(+++)(100%; CD30(-); CD56(-); CD57(+/+++)70%; Toxoplasma(-); EBER(-); PanCK(-); CD68(-)(Histiocytes +); Ki67(+++)iki 70%; CMV/polyoma (SV40)(-); CD23/CD21(-)(FDC absent).  
CD138+ clusters: Ig kappa/lambda+ (politypic).  
 
MOLECS: CLONAL TCRB V-D-J1/2, D-J1/2 ir TCRG V-J .  
IGH ir IGK lokusuose NON CLONAL.  
 
PROPOSAL: Atypical EBER(-) T lymhoid cytotoxic lymphoproliferation of CNS with abberant immunophenotype: CD3/CD2/CD8/CD57+ > CD5+; CD7/CD4(-); CD56/CD30(-); TIA1/Granzym B+; EBER(-); Ki67 high up to 70%. Hemophagocytosis. Prominent arteriosclerosis/atheromatosis.  
Clinical correlation is essential: viral infections? LDH? leukemic? extranodal/nodal lesions? due to possible T LPD: T large granular lymphocytic leukaemia?