title: Transient subsolid nodules in patients with extrapulmonary malignancies: their frequency and differential features.
abstract: BACKGROUND
  For pulmonary subsolid nodules (SSNs) in patients with extrapulmonary malignancies, it is still unclear what proportion of SSNs is transient and how we can more accurately diagnose these transient SSNs.
  
  
  OBJECTIVE
  To investigate the frequency of transient SSNs and their differentiating clinical and thin-section computed tomography (CT) features in patients with extrapulmonary malignancies.
  
  
  METHODS
  From January 2005 to February 2012, 78 SSNs in 63 individuals (30 men and 33 women; mean age, 55.1 years ± 15.5) with extrapulmonary malignancies were identified. Their clinical and thin-section CT characteristics were reviewed and compared between transient and persistent SSNs. Differentiating factors and their performance were also measured.
  
  
  RESULTS
  Thirty-six of the 78 SSNs (46.2%) were transient. Between transient and persistent SSNs, there were significant differences in patients' age, sex, detection mode, and the presence of eosinophilia, lesion multiplicity, lesion margin, and pleural retraction (P < 0.05). Multivariate analysis revealed that follow-up detected SSNs (adjusted odds ratio [OR], 38.88), multiple lesions (OR, 7.64), and an ill-defined nodular margin (OR, 11.93) were significant discriminators of transient SSNs (P < 0.05). Discrimination of transient SSNs was significantly better upon incorporating both clinical and thin-section CT features than using clinical features alone (P < 0.05).
  
  
  CONCLUSIONS
  Approximately half of the SSNs detected in patients with extrapulmonary malignancies were transient. Transient SSNs in these patients can be very accurately differentiated using their thin-section CT and clinical features.
authors.affiliation: Department of Radiology, Seoul National University College of Medicine, Seoul, Republic of Korea Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, Republic of Korea.
authors.forename: Won Seok
authors.initials: WS
authors.lastname: Choi
authors.affiliation: Department of Radiology, Seoul National University College of Medicine, Seoul, Republic of Korea Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, Republic of Korea Cancer Research Institute, Seoul National University, Seoul, Republic of Korea cmpark@radiol.snu.ac.kr.
authors.forename: Chang Min
authors.initials: CM
authors.lastname: Park
authors.affiliation: Department of Radiology, Seoul National University College of Medicine, Seoul, Republic of Korea Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, Republic of Korea.
authors.forename: Yong Sub
authors.initials: YS
authors.lastname: Song
authors.affiliation: Department of Radiology, Seoul National University College of Medicine, Seoul, Republic of Korea Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, Republic of Korea.
authors.forename: Sang Min
authors.initials: SM
authors.lastname: Lee
authors.affiliation: Department of Radiology, Seoul National University College of Medicine, Seoul, Republic of Korea Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, Republic of Korea.
authors.forename: Jae Yeon
authors.initials: JY
authors.lastname: Wi
authors.affiliation: Department of Radiology, Seoul National University College of Medicine, Seoul, Republic of Korea Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, Republic of Korea Cancer Research Institute, Seoul National University, Seoul, Republic of Korea.
authors.forename: Jin Mo
authors.initials: JM
authors.lastname: Goo
mesh_terms: D003287:Contrast Media; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000556:secondary*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011856:Radiographic Image Enhancement / Q000379:methods; D056910:Republic of Korea; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media
keywords: Subsolid nodule; extrapulmonary malignancies; transient nodule