Fig. 3

(Case 4) H&E, immunohistochemical, and FISH analysis of PTC coexisting with FL(100x) (red arrow: PTC, black arrow: FL). PTC shows weak positivity for BCL-2. FL had a low Ki67 proliferation rate. (A) H&E; positive for (B) CD20, (C) BCL2, (E) CD10, (F) BCL6, (G) Ki67. FISH reveals BCL2 (yellow arrow) rearrangements in FL (D), with no genetic rearrangements in PTC (H).