Subtypes of grade 3 follicular lymphoma.

(A) Grade 3a contains more than 15 centroblasts/hpf in a background of centrocytes; (B) grade 3b consists of sheets of centroblasts with no admixed centrocytes; (C) grade 3bs consists predominantly of small centroblasts with no admixed centrocytes; a large centroblast (arrow) is shown for comparison; and (D) large cleaved cell lymphoma consisting of intermediate-sized to large cells with irregular, cleaved, or twisted nuclei, fine chromatin, and inconspicuous nucleoli; a large centroblast (arrow) and small centrocyte (arrowhead) are shown for comparison (H&E stains, original magnification, × 400).