Epstein-Barr virus-induced transformation of cutaneous plasmacytoma into CD30+ diffuse large B-cell lymphoma

A unique, previously unreported case of transformation of cutaneous plasmacytoma into CD30+ large B-cell lymphoma is described. Both neoplastic components were immunophenotypically distinct. The plasma cells were CD20-, CD30-, CD43+, CD45+, lambda +; the blasts were CD20+, CD30+, CD43-, and CD45-. The large B-cell lymphoma has gradually become a predominant component of the neoplastic nodules. While plasma cells and blasts were both positive for Epstein-Barr virus-encoded nuclear RNAs (EBER-1), the EBV-latent membrane antigen 1 (EBV-LMP1) was expressed only in the minority of the blasts and not in the plasma cells. The neoplastic process has remained confined to the skin for more than six years since its development.