title: Imaging features and outcomes in 10 cases of idiopathic azygos vein aneurysm.
abstract: BACKGROUND
  Idiopathic azygos vein aneurysm (AVA) is rare. This retrospective study evaluated the imaging features and outcomes in 10 cases of idiopathic AVA.
  
  
  METHODS
  We retrospectively evaluated 10 patients with surgically proven or typical imaging features of idiopathic AVA encountered in our institution between 1990 and 2012. Chest roentgenography and computed tomography (CT) were performed in all 10 patients, and magnetic resonance imaging (MRI) was performed in 4 of these patients. The clinical features, AVA morphologic characteristics, and outcomes were analyzed.
  
  
  RESULTS
  Chest roentgenograms showed a right paratracheal nodule or mediastinal mass in 7 cases. CT and MRI disclosed 4 thrombosed saccular AVAs (short axis, 3-6 cm; mean, 4.7 cm) and 6 fusiform AVAs (short axis, 2.2-3 cm; mean 2.7 cm). Two large saccular AVAs that presented with chest tightness were resected shortly after diagnosis. One saccular AVA manifested as a pulmonary embolism, whereas the remaining AVA was asymptomatic; they showed 25% to 40% short-axis growth in a 3- to 5-year interval before subsequent AVA resection. Conversely, all 6 fusiform AVAs were asymptomatic and found incidentally, remaining rather stable with less than 8% short-axis growth during 3 to 8 years of follow-up. Compared with fusiform AVAs, saccular AVAs were larger and had a greater frequency of AVA-related symptoms, intralesional thromboses, and greater than 20% short-axis growth during the follow-up period.
  
  
  CONCLUSIONS
  Saccular AVAs are larger than fusiform aneurysms, presenting with greater frequency of chest symptoms, intralesional thrombosis, considerable lesion growth, and need for surgical intervention. In contrast, fusiform AVAs are asymptomatic and rather stable in long-term follow-up.
authors.affiliation: Department of Radiology, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan. Electronic address: sfa.ko@msa.hinet.net.
authors.forename: Sheung-Fat
authors.initials: SF
authors.lastname: Ko
authors.affiliation: Department of Radiology, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan.
authors.forename: Chung-Cheng
authors.initials: CC
authors.lastname: Huang
authors.affiliation: Department of Pathology, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan.
authors.forename: Jui-Wei
authors.initials: JW
authors.lastname: Lin
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan.
authors.forename: Hung-I
authors.initials: HI
authors.lastname: Lu
authors.affiliation: Department of Emergency Medicine, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan.
authors.forename: Chia-Te
authors.initials: CT
authors.lastname: Kung
authors.affiliation: Department of Radiology, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan.
authors.forename: Shu-Hang
authors.initials: SH
authors.lastname: Ng
authors.affiliation: Department of Radiology, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan.
authors.forename: Yung-Liang
authors.initials: YL
authors.lastname: Wan
authors.affiliation: Department of Cardiology, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung, Taiwan.
authors.forename: Hon-Kan
authors.initials: HK
authors.lastname: Yip
mesh_terms: D000328:Adult; D000368:Aged; D000783:Aneurysm / Q000175:diagnosis* / Q000601:surgery*; D001401:Azygos Vein; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome