title: [Primary extranodal lymphomas: analyses of clinical characteristics and misdiagnoses of 139 cases].
abstract: OBJECTIVE
  To evaluate the incidence, extranodal sites, clinical characteristics and misdiagnosis rate of primary extranodal lymphomas.
  
  
  METHODS
  A retrospective survey of 139 patients of primary extranodal lymphomas from Peking University First Hospital was completed with a view to improving our knowledge of the incidence, extranodal sites, clinical characteristics and misdiagnosis rate of primary extranodal lymphomas.
  
  
  RESULTS
  (1) We studied 139 patients with primary extranodal lymphoma, who constituted 30.3% of 458 patients with lymphoma in Peking University First Hospital between 12/1976 and 2/2002. (2) The developing sequence of common extranodal sites was: gastrointestinal lymphoma 20.9% (29/139), nasal lymphoma 18.7% (26/139), Waldeyer's ring lymphoma 12.9% (18/139), splenic lymphoma 10.8% (15/139), and cutaneous lymphoma 6.5% (9/139). (3) Misdiagnosis rate of primary extranodal lymphoma was 80.6%, and misdiagnosis rate of nodal lymphoma was 28.5%. (4) Symptoms and signs of extranodal lymphoma were quite different based on different extranodal sites and had no specific characteristics.
  
  
  CONCLUSIONS
  Primary extranodal lymphoma is relatively common. Misdiagnosis rate is very high because extranodal sites are very extensive and signs are of no specific characteristics. We should pay more attention to primary extranodal lymphoma, and get a correct diagnosis as soon as possible.
authors.affiliation: Department of Hematology, Peking University First Hospital, Beijing 100034, China. cenxn@yahoo.com
authors.forename: Xinan
authors.initials: X
authors.lastname: Cen
authors.forename: Mingxin
authors.initials: M
authors.lastname: Ma
authors.forename: Hui
authors.initials: H
authors.lastname: Guo
authors.forename: Shulan
authors.initials: S
authors.lastname: Wu
authors.forename: Ying
authors.initials: Y
authors.lastname: Wang
authors.forename: Zhixiang
authors.initials: Z
authors.lastname: Qiu
authors.forename: Wensheng
authors.initials: W
authors.lastname: Wang
authors.forename: Jinping
authors.initials: J
authors.lastname: Ou
authors.forename: Weilin
authors.initials: W
authors.lastname: Xu
authors.forename: Yujun
authors.initials: Y
authors.lastname: Dong
authors.forename: Ping
authors.initials: P
authors.lastname: Zhu
authors.forename: Jiren
authors.initials: J
authors.lastname: Yu
mesh_terms: D003951:Diagnostic Errors; D006801:Humans; D008223:Lymphoma / Q000175:diagnosis*; D012189:Retrospective Studies