Morphology of ALK and DLBCL. (A) H&E-stained section of the diagnostic lymph node biopsy from case 1 showing neoplastic cells with immunoblastic and plasmablastic features. (B) The ALK-1 stain reveals fine granular cytoplasmic localization of the ALK protein (inset). Original magnifications: ×400 (A-B); ×800 (inset).