CASE IS OPEN:  
 
37 yrs old lady with neck lymphadenopathy, fever, enlarged salivary gland. After diagnosis of T LBL redirected to hemato dept. Bone marrow positive.  
EPISODE 1: LYMPH NODE BIOPSY (depicted): T LBL.  
 
- IH (heterogenous; "cortical" ): TdT+; CD1a+; Bcl2+; LMO2+; CD4/CD8+; CD7+ > CD3/CD2/CD5+ > CD34+; CD10+/-; CD68+/-; Bcl6(-/+); HLA DR(-); CD117/MPO/CD123/CD163/CD15/CD14(-); CD20/CD79a/Pax5(-); Ki67 index up to 60%.  
OF NOTE: focal CD68+ fade on PALE BLAST nodules.  
 
EPISODE 2: bone marrow (depicted): tumor BINARY spread as in biopsy. NOT ENOUGH for IH (nodule is gone on CD3)  
EPISODE 3: core biopsy (for molecular tracking and rest for histology)(depicted): T LBL (binary).  
 
FLOW (ASPIRATE): BLASTS ~8% : CD45+focal, CD7+het, cCD3+focal, CD4+focal, CD5+focal, CD10+focal, CD33+dim, CD34+dim, CD38+strong, CD99+dim, HLA-DR+, cTdT+dim, CD48-/+dim, CD1a-, CD2-, CD3-, CD8-, CD13-, CD15-, CD19-, CD56/16-, CD117-, cCD79a-, cMPO-.  
Immunophenotype compatible with pro-T ALL differentiating with early T precursor (ETP) ALL (CD1a/CD8-, CD33+, CD5 focal)  
 
MOLECS: VPN without changes (low blast amount).  
FLT3 ITD NEGATIVE;  
BCR/ABL1 t(9;22)(q34;q11) NEGATIVE;  
Other pending.  
 
PROPOSED DIAGNOSIS: T lymphoblastic lymphoma/leukaemia, IH close to ETP-T ALL (focal CD68+ ?).  
 
DIAGNOSTIC PROBLEM: 2 populations of blasts, VARIATING differently in lymph node(CD1a+; 2 populations), core biopsy (CD1a(-/+); 2 populations) and bone marrow (2 populations):  
- CD4+CD7+ TdT(-) anonymous (PALE blasts/ nodules forming);  
- TdT+ lymphoblastic classic (more diffuse DARK blasts).  
It seems represent different stages of T LBLasts.  
 
ThankYouforHelp2019.

tzankov 2019-01-29 17:05

Difficult case. Nevertheless...basically I think that the patient is suffering from one disease, T-LBL, and the blasts display some degree of plasticity at the various obtained biopsy sites. Esepecially early T-cells have much in common with monocytopoiesis and these two lines can switch to each other, therefore I would consider e.g. dimCD4 or dimCD68 being compatible with ETP-ALL. This is rather not the case for CD1a, which defines cortical LBL, the double-positivity for CD4 and CD8 also supports this, and - finally - since you have much more tumor cells (than the FACS) to determine the phenotype, I would rather suggest trusting histopathology to determine the exact LBL subtype. I favor cortical T-LBL.

ugnius 2019-01-31 12:11

Thanx a lot.