Analysis of KSHV-associated GLD.
(A) Histologic and immunophenotypic features of KSHV-associated GLD in case 1: The germinal centers are replaced by large cells with a moderate amount of amphophilic cytoplasm and a large vesicular nucleus containing 1 or 2 prominent nucleoli. These large cells coalesce and form confluent aggregates (panels i-ii, hematoxylin-eosin staining). They express high levels of cytoplasmic Ig (monotypic Igλ, IgM/D) and are therefore termed plasmablasts (iii-vi). Plasmablasts are positive for both KSHV (vii) and EBV (viii), and most of them express vIL-6 (ix). CD21 staining shows that KSHV-positive cells occur within meshworks of follicular dendritic cells (x). Original magnification i, × 40; ii-iv, × 600; vii-x, × 400. (B) Clonality analysis of KSHV-associated GLD in case 1: FR3-JH PCR analysis of DNA samples from whole tissue sections shows a weak dominant band in a polyclonal background. FR2-JH PCR analysis of microdissected KSHV-positive foci (A1 and A2 from case 1) shows an oligoclonal pattern.
