Germinal Center Cytokines Driven Epigenetic Control of Epstein-Barr Virus Latency Gene Expression.

Epstein-Barr virus (EBV) persistently infects 95% of adults worldwide and is associated with multiple human lymphomas that express characteristic EBV latency programs used by the virus to navigate the B-cell compartment. Upon primary infection, the EBV latency III program, comprised of six Epstein-Barr Nuclear Antigens (EBNA) and two Latent Membrane Protein (LMP) antigens, drives infected B-cells into germinal center (GC). By incompletely understood mechanisms, GC microenvironmental cues trigger the EBV genome to switch to the latency II program, comprised of EBNA1, LMP1 and LMP2A and observed in GC-derived Hodgkin lymphoma.

CD4-Negative Variant of Cutaneous Blastic Plasmacytoid Dendritic Cell Neoplasm With a Novel PBRM1 Mutation in an 11-Year-Old Girl.

Objectives: We report a rare case of CD4- cutaneous blastic plasmacytoid dendritic cell neoplasm (BPDCN) with a novel PBRM1 mutation.

Methods: An 11-year-old girl presented with an enlarged mass on her left arm and underwent an incisional biopsy.

Results: Histopathologic examination and immunohistochemistry studies showed a monotonous proliferation of blasts that were CD4-, CD56+, and CD123+.