title: Mediastinal lymph nodes and pulmonary nodules in children: MDCT findings in a cohort of healthy subjects.
abstract: OBJECTIVE
  Existing data are very limited on incidentally detected pulmonary nodules or mediastinal lymph nodes in healthy children who undergo chest MDCT. We aimed to evaluate the prevalence, distribution, and average dimensions of these occasional findings in a cohort of otherwise healthy patients.
  
  
  METHODS
  Two radiologists reviewed in consensus the scans of patients referred for chest MDCT during the preoperative workup for pectus carinatum or pectus excavatum treatments. Exclusion criteria included the presence of any documented malignancy (by date of MDCT or during the 2 years after the examination), history of recent infections, or trauma. Patients' records were assessed after 2 years for the development of any malignancy.
  
  
  RESULTS
  A total of 99 individuals (63 boys, 36 girls; mean age, 13.5 years; range, 4-18 years) who fulfilled the study criteria were evaluated. The presence of at least one pulmonary nodule was observed in 75% of the patients, with a mean diameter of 2.8 mm. Of a total number of 225 pulmonary nodules, only 24 (10.7%) were calcified. Mediastinal lymph nodes were also identified in 81% of the cases, with a maximum diameter of 7 mm (smallest axis).
  
  
  CONCLUSIONS
  The presence of pulmonary nodules or mediastinal lymph nodes on the basis of preoperative chest MDCT scans in healthy children is frequent. Given that 95% of the nodules and 100% of the lymph nodes measured less than 6 mm and 7 mm, respectively, we conclude that incidental findings under these limits are very unlikely to be pathologic.
authors.affiliation: 1 Department of Radiology, Federal University of Rio de Janeiro, Professor Rodolpho Paulo Rocco St, 255, ZC: 21941-913, Rio de Janeiro, Brazil.
authors.forename: Giordano Rafael Tronco
authors.initials: GR
authors.lastname: Alves
authors.forename: Edson
authors.initials: E
authors.lastname: Marchiori
authors.forename: Klaus Loureiro
authors.initials: KL
authors.lastname: Irion
authors.forename: Marcos Duarte
authors.initials: MD
authors.lastname: Guimarães
authors.forename: Carol Fernandes Jerzewski Sotero
authors.initials: CF
authors.lastname: da Cunha
authors.forename: Vinícius Valério Silveira
authors.initials: VV
authors.lastname: de Souza
authors.forename: Bruno
authors.initials: B
authors.lastname: Hochhegger
mesh_terms: D000293:Adolescent; D001938:Brazil / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D033162:Incidental Findings; D008198:Lymph Nodes / Q000000981:diagnostic imaging*; D008207:Lymphatic Metastasis; D008297:Male; D008482:Mediastinum / Q000000981:diagnostic imaging*; D061330:Multidetector Computed Tomography / Q000706:statistics & numerical data*; D015995:Prevalence; D012016:Reference Values; D015203:Reproducibility of Results; D012307:Risk Factors; D012680:Sensitivity and Specificity; D003074:Solitary Pulmonary Nodule / Q000000981:diagnostic imaging* / Q000453:epidemiology*
keywords: CT; pectus carinatum; pectus excavatum; pediatric radiology