title: Florid CD4+, CD56+ T-cell infiltrate associated with Herpes simplex infection simulating nasal NK-/T-cell lymphoma.
abstract: We report a case of Herpes simplex virus (HSV) infection of the nasopharynx associated with a dense CD4+, CD56+ T-cell infiltrate that simulated lymphoma on clinical, histologic, and immunophenotypic grounds. Histologic examination showed a tumorlike lymphoid infiltrate with extensive necrosis. Multinucleated giant cells with "ground-glass" nuclei characteristic of HSV were observed in necrotic areas but were not prominent. Immunohistochemical studies of the lymphoid infiltrate revealed a predominance of T cells, positive for CD3, CD4, CD5, and CD56. Immunohistochemical staining with HSV antibody was focally positive in the multinucleated giant cells. Molecular studies using PCR and Southern blot were positive for HSV Type II. PCR studies for T-cell receptor gamma and immunoglobulin heavy chain gene rearrangements showed no evidence of a clonal population. In situ hybridization studies for Epstein-Barr virus (EBV) were negative. The clinical presentation of a large fungating mass, the extent of the lymphoid infiltrate, and the expression of CD56 all raised the possibility of a nasal NK/T cell lymphoma. However, the presence of HSV, lack of angioinvasion and angiodestruction, absence of EBV, and polyclonal T-cell nature of the infiltrate argued against this diagnosis. Although prior studies have not fully characterized the immunophenotypic features of the lymphocyte response to HSV in infected tissues, we postulate that the CD56+, CD4+ T-cell reaction represents a florid antiviral immune response.
authors.affiliation: Laboratory of Pathology, Hematopathology Section, National Cancer Institute, National Institutes of Health, Building 10, Room 2N202, 10 Center Drive MSC-1500, Bethesda, MD 20892-1500, USA.
authors.forename: Lekidelu
authors.initials: L
authors.lastname: Taddesse-Heath
authors.forename: Jeffery I
authors.initials: JI
authors.lastname: Feldman
authors.forename: Gary A
authors.initials: GA
authors.lastname: Fahle
authors.forename: Steven H
authors.initials: SH
authors.lastname: Fischer
authors.forename: Lynn
authors.initials: L
authors.lastname: Sorbara
authors.forename: Mark
authors.initials: M
authors.lastname: Raffeld
authors.forename: Elaine S
authors.initials: ES
authors.lastname: Jaffe
mesh_terms: D000328:Adult; D015139:Blotting, Southern; D015704:CD4 Antigens / Q000378:metabolism; D019002:CD56 Antigen / Q000378:metabolism; D004279:DNA, Viral / Q000032:analysis*; D003937:Diagnosis, Differential; D005260:Female; D015726:Giant Cells / Q000473:pathology / Q000821:virology; D006561:Herpes Simplex / Q000150:complications* / Q000276:immunology* / Q000473:pathology*; D006801:Humans; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D016399:Lymphoma, T-Cell / Q000473:pathology; D009305:Nasopharynx / Q000473:pathology* / Q000821:virology; D016133:Polymerase Chain Reaction; D013601:T-Lymphocytes / Q000276:immunology* / Q000378:metabolism
chemical_list: D015704:CD4 Antigens; D019002:CD56 Antigen; D004279:DNA, Viral