title: Epstein-Barr virus-related atypical lymphoproliferative disorders in Waldeyer's ring: a clinicopathological study of 9 cases.
abstract: OBJECTIVE
  Because of the small biopsy specimens in the Waldeyer's ring (WR) the differential diagnosis between Epstein-Barr virus (EBV)-associated lymphoproliferative disorder (LPD) and malignant lymphoma is occasionally difficult. We report here clinicopathological, immunohistochemical and genotypic findings of 9 cases of EBV-associated LPDs in WR.
  
  
  METHODS
  Using formalin-fixed paraffin-embedded sections, histological analyses, immunohistochemistry, in situ hybridization and polymerase chain reaction were performed.
  
  
  RESULTS
  Clinically, all 9 cases showed more than one atypical clinical finding of infectious mononucleosis including absence of systemic symptoms, absence of atypical lymphocytosis and age over 30 years. Histologically, 3 types were delineated: (1) Hodgkin lymphoma-like (n = 1), (2) T cell/histiocyte-rich large B cell lymphoma-like (n = 4), and (3) marginal zone B cell lymphoma of mucosa-associated lymphoid tissue (MALT)-like (n = 4). The in situ hybridization study demonstrated EBV-encoded small RNA (EBER)+ cells in all 9 lesions. The immunohistochemical and flow cytometry study demonstrated the reactive nature of the B cells in all 9 lesions. However, 3 of our 7 cases examined demonstrated immunoglobulin heavy chain gene rearrangement on PCR study. There was no development of B cell lymphoma in any of the 3 lesions demonstrating IgH rearrangement.
  
  
  CONCLUSIONS
  EBV-associated LPDs of the WR showed marked histological diversity. Among these, a MALT-like pattern was frequently seen. Marginal zone B cell lymphoma frequently affects WR. We emphasized that EBV-associated LPD should be added to the differential diagnosis of primary tonsillar MALT-type lymphoma.
authors.affiliation: Department of Anatomic and Diagnostic Pathology, Dokkyo University School of Medicine, Mibu, Japan. k-masaru @ dokkyomed.ac.jp
authors.forename: Masaru
authors.initials: M
authors.lastname: Kojima
authors.forename: Naoya
authors.initials: N
authors.lastname: Nakamura
authors.forename: Hideaki
authors.initials: H
authors.lastname: Itoh
authors.forename: Ken
authors.initials: K
authors.lastname: Shimizu
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Shimizu
authors.forename: Hazuki
authors.initials: H
authors.lastname: Matsuda
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Tamaki
authors.forename: Nobuhide
authors.initials: N
authors.lastname: Masawa
authors.forename: Shigeo
authors.initials: S
authors.lastname: Nakamura
mesh_terms: D000328:Adult; D001402:B-Lymphocytes / Q000473:pathology; D005260:Female; D004854:Herpesvirus 4, Human / Q000235:genetics; D006644:Histiocytes / Q000473:pathology; D006689:Hodgkin Disease / Q000150:complications / Q000473:pathology; D006801:Humans; D006965:Hyperplasia / Q000150:complications / Q000473:pathology; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D008223:Lymphoma / Q000150:complications / Q000473:pathology; D016393:Lymphoma, B-Cell / Q000150:complications / Q000473:pathology; D018442:Lymphoma, B-Cell, Marginal Zone / Q000150:complications / Q000473:pathology; D008232:Lymphoproliferative Disorders / Q000150:complications / Q000473:pathology* / Q000821:virology*; D008297:Male; D008875:Middle Aged; D011230:Precancerous Conditions / Q000150:complications / Q000473:pathology