title: [Clinical analysis of 438 patients with essential thrombocythemia].
abstract: OBJECTIVE
  To analyse the clinical feature and natural course of essential thrombocythemia (ET).
  
  
  METHODS
  A retrospective analysis was conducted in ET patients treated in our hospital during May 1980 to December 2006.
  
  
  RESULTS
  Four hundred and thirty eight patients (201 males and 237 females with a median age of 48 years) were diagnosed. Hemorrhage occurred in 101 cases (23.1%), thrombosis in 86 cases (19.6%), and both hemorrhage and thrombosis in 13 cases (3.0%). Splenomegaly occurred in 150 cases and hepatomegaly occurred in 60 cases. One hundred and forty-nine cases (34%) had no symptoms at diagnosis and 145 cases (33.1%) confirmed by routine blood tests due to other diseases. The median platelet count at diagnosis was 1000 x 10(9)/L [(533 -3740) x 10(9)/L]. Bone marrow biopsy was performed in 255 cases which showed mainly increase of enlarged mature megakaryocytes with hyper-lobulated nuclei and local proliferation of reticular fiber was revealed in 51 cases. JAK2V617F mutation was detected in 90(78.9%) of 114 patients studied. Karyotype analysis was performed in 180 cases and 6 (3.3%) had clonal chromosomal aberrations. Two hundred and sixty-one patients were followed up over 12 months with a median of 60 months (range from 12 to 300 months). Seventeen cases (6.5%) evolved into marrow fibrosis (MF) and one case into polycythemia vera (PV). One case evolved into PV 6 years and then MF 20 years after diagnosis of ET. Three cases developed acute monocyte leukemia (M5), myelodysplastic syndrome (MDS) and multiple myeloma (MM), respectively.
  
  
  CONCLUSIONS
  ET is a chronic myeloproliferative disorder characterized predominantly by thrombocytosis and hemorrhage. The percentage of asymptomatic cases is high. The prognoses for most cases were good with a few cases may evolve into MF.
authors.affiliation: Institute of Hematology and Blood Diseases Hospital, CAMS and PUMC, Tianjin 300020, China.
authors.forename: Hai-Feng
authors.initials: HF
authors.lastname: Lan
authors.forename: Zhi-Hong
authors.initials: ZH
authors.lastname: Fang
authors.forename: Yue
authors.initials: Y
authors.lastname: Zhang
authors.forename: Xiao-Yan
authors.initials: XY
authors.lastname: Wang
authors.forename: Feng
authors.initials: F
authors.lastname: Xue
authors.forename: Lei
authors.initials: L
authors.lastname: Zhang
authors.forename: Zhen-Xing
authors.initials: ZX
authors.lastname: Guo
authors.forename: Xun-Wei
authors.initials: XW
authors.lastname: Dong
authors.forename: Shang-Zhu
authors.initials: SZ
authors.lastname: Li
authors.forename: Yi-Zhou
authors.initials: YZ
authors.lastname: Zheng
authors.forename: Feng-Kui
authors.initials: FK
authors.lastname: Zhang
authors.forename: Lin-Sheng
authors.initials: LS
authors.lastname: Qian
authors.forename: Lin-Xiang
authors.initials: LX
authors.lastname: Ji
authors.forename: Zhi-Jian
authors.initials: ZJ
authors.lastname: Xiao
authors.forename: Ren-Chi
authors.initials: RC
authors.lastname: Yang
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012189:Retrospective Studies; D013920:Thrombocythemia, Essential / Q000235:genetics / Q000473:pathology; D055815:Young Adult