title: Inflammatory pseudotumor of the spleen associated with a clonal Epstein-Barr virus genome. Case report and review of the literature.
abstract: We report a case of an inflammatory pseudotumor (IPT) of the spleen occurring in an 81-year-old woman with a history of a monoclonal gammopathy of undetermined significance. Eighteen-month follow-up after splenectomy demonstrated no tumor recurrence or progression of underlying plasma cell disease. Histologic examination of the tumor demonstrated a polymorphic population of inflammatory and epithelioid and spindle cells. Immunophenotyping showed large numbers of T cells, B cells, and polyclonal plasma cells. The epithelioid and spindle cells were positive for vimentin and CD68 but lacked expression of follicular dendritic cell markers and actin. Epstein-Barr virus (EBV) genome was identified in the epithelioid and spindle cell population by in situ hybridization using probes specific for EBV-encoded RNAs (EBER1 and EBER2). Southern blot analysis of digested DNA extracted from the tumor using an EBV-specific probe (XhoI) demonstrated the presence of a single high-intensity band, indicative of EBV monoclonality. While there have been 2 previous reports of hepatic IPTs containing a monoclonal population of EBV-infected tumor cells, this is the first report of such an association occurring in the spleen. The presence of clonal EBV DNA suggests some splenic IPTs may be true neoplasms.
authors.affiliation: Dept of Pathology, Mayo Clinic, 200 First St SW, Rochester, MN 55905, USA.
authors.forename: Jason T
authors.initials: JT
authors.lastname: Lewis
authors.forename: Robyn L
authors.initials: RL
authors.lastname: Gaffney
authors.forename: Mary B
authors.initials: MB
authors.lastname: Casey
authors.forename: Michael A
authors.initials: MA
authors.lastname: Farrell
authors.forename: William G
authors.initials: WG
authors.lastname: Morice
authors.forename: William R
authors.initials: WR
authors.lastname: Macon
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002999:Clone Cells; D004279:DNA, Viral / Q000032:analysis; D015622:Epithelioid Cells / Q000473:pathology / Q000821:virology; D020031:Epstein-Barr Virus Infections / Q000150:complications / Q000473:pathology*; D005260:Female; D016679:Genome, Viral; D006104:Granuloma, Plasma Cell / Q000473:pathology* / Q000601:surgery / Q000821:virology; D004854:Herpesvirus 4, Human / Q000235:genetics* / Q000302:isolation & purification; D006801:Humans; D007124:Immunoenzyme Techniques; D016130:Immunophenotyping; D017403:In Situ Hybridization; D008214:Lymphocytes / Q000473:pathology / Q000821:virology; D012367:RNA, Viral / Q000032:analysis; D011860:Radiography, Abdominal; D013158:Splenic Diseases / Q000473:pathology* / Q000601:surgery / Q000821:virology; D014057:Tomography, X-Ray Computed
chemical_list: D004279:DNA, Viral; C099537:Epstein-Barr virus encoded RNA 1; C106732:Epstein-Barr virus encoded RNA 2; D012367:RNA, Viral