CASE IS OPEN FOR DISCUSSION:  
 
39yrs old male with axillar lymph node core biopsy (not included) and excisional biopsy.  
 
Anamnesis/Clinical : Skin eruption on Amoxyclav use due to lymphadenopathy (from 2021 m. January: hypoechoic round nodules, max polycyclic ~18 x 37 mm with irregular vascularity.  
EBV: found: DNA copies/ml 174.  
 
HISTO: Vaguelly nodular lymphoid back with giant CHL like cells and slight thropism to sinuses. Partial effacement.  
 
IH (OVERSTAINED, SELECTED MARKERS):  
GIANT CELLS: CD30(+++)(cytopl.) 100%; EMA/ALK1/HHV8/CD15/EBER(-); GATA3+ (weak); Bcl2 (++/+++)(cytopl.) 80%; LCA(+++)(membr. cytopl.) 100%; PAX5(-); CD20/CD79a(-); BOB1(++/+++)(nuclear) 100%; OCT2(-); CD3(++)(cytopl) 100%; CD4(+)(membr. cytopl) 90%; CD2/CD5/CD7/CD8(-); EBER(-)(scatterEd Small bystanders+); Bcl6(+)(nuclear weak) singles; CD10(-); Ki67 prolif. index up to 100% (+++/++)(nuclear); Ig kappa/lambda(-); Fascin(-); Perforin(-); TIA1/GranzymB (++/+++)(cytopl.) 80%; PD-L1(?)(noise from CD68+ macrophages around).  
BACKSTAGE: predominant CD3/CD2/CD5/CD7+, CD4+ > CD8+ T population without rosetting; ICOS+ > PD1+ interstitial population; CD57+ dispersed scattered; CD10(-); Bcl6(+)(silpna r-ja) scattered.  
CD20/CD79a+ follicular and interstitial population with regular or deformed/expanded networks of FDC CD21/CD23+.  
Scattered CD23+ lymphos. Polytypic plasma cells Ig kappa/lambda+.  
 
MOLECULAR:  
IGH, IGK ir IGL NON CLONAL;  
TCRB, TCRG ir TCRD: CLONAL TCRB V-D-J1/2 ir TCRG loccuses (identical to core biopsy)  
 
PROPOSAL:  
GREY ZONE LYMPHOMA WITH ALCL >> AND CHL grade II/syntytial FEATURES (partial LN involvement/LCA and BOB1+ ?)?  
Immunophenotype: CD30+; CD15(-); Granzym B/TIA1+; (!) CD3/CD4+ (!); LCA/BOB1+ (!); EBER(-); Bcl6-/+(weak single); Perforin(-); Fascin(-); Oct2/Pax5/CD20/CD79a(-); CD2/CD7/CD5/CD8(-); Ki67 prolif. index up to 100%.  
 
The case dedicated to dr.F.Fend talk on EAHP 2021 (grey zone T NHL vs CHL).  
 
ThankYouaLot.