Diagnostic features of FLIS and PFL
| FLIS . | PFL . |
|---|---|
| Architecture intact | Altered architecture |
| Follicle size normal | Follicle size often expanded |
| Involved follicles widely scattered | Involved follicles grouped together in LN |
| Intact cuff with sharp edge to GC | Blurred edge to GC and attenuated cuff |
| Very strong expression of BCL2 and CD10 | BCL2 and CD10 more variable in intensity |
| Almost pure centrocytes | Centrocytes with few centroblasts |
| Atypical cells confined to GC | Atypical cells (CD10+/BCL2+ B cells) may be found outside the GC |
| FLIS . | PFL . |
|---|---|
| Architecture intact | Altered architecture |
| Follicle size normal | Follicle size often expanded |
| Involved follicles widely scattered | Involved follicles grouped together in LN |
| Intact cuff with sharp edge to GC | Blurred edge to GC and attenuated cuff |
| Very strong expression of BCL2 and CD10 | BCL2 and CD10 more variable in intensity |
| Almost pure centrocytes | Centrocytes with few centroblasts |
| Atypical cells confined to GC | Atypical cells (CD10+/BCL2+ B cells) may be found outside the GC |
GC indicates germinal center.