title: Discriminating preoperative features of pleuropulmonary blastomas (PPB) from congenital cystic adenomatoid malformations (CCAM): a retrospective, age-matched study.
abstract: BACKGROUND
  The etiopathogenesis of pleuropulmonary blastoma (PPB) and its relationship to congenital cystic adenomatoid malformation (CCAM) remain controversial. Our recent analysis indicates that both the co-incidental occurrence and the outcome of PPB among CCAM patients are significant. We report here on our efforts to determine clinical and radiological features discriminating PPB from CCAM preoperatively.
  
  
  METHODS
  A retrospective analysis of all patients treated for PPB and CCAM between 1981 and 2008 at 2 tertiary academic centers under a centralized, single payer healthcare system was performed (REB#1000013239). Clinical, radiological and demographic data were analyzed. PPB patients were secondarily age matched with CCAM patients (± 10% age difference in months), and clinical, radiological and demographic variables were compared. Descriptive statistics and non-parametric analysis were used.
  
  
  RESULTS
  A total of 10 PPB patients was identified. Median age at diagnosis was 24 months; the male to female ratio was 5:5. No PPB patients had an antenatal diagnosis (p<0.01). 9 were symptomatic, with symptoms including dyspnea (7/10), upper respiratory infection (6/10), poor weight gain (3/10), and 1 patient was asymptomatic. 5 of 10 patients had solid parts on CT, of which 4 out of 5 were diagnosed preoperatively as PPB and 1 out of 5 as CCAM. 5 of 10 were predominantly cystic of which none was diagnosed preoperatively as PPB (p=0.0476). Given that most CCAM patients are now diagnosed antenatally, only 5 PPB patients could be age-matched with CCAM patients. In the predominantly cystic PPB patients (n=5), no significant discriminating clinical and radiological features were identifiable when compared preoperatively with age-matched CCAM patients.
  
  
  CONCLUSIONS
  PPB patients continue to represent a diagnostic challenge. Asymptomatic and predominantly cystic PPB remain indistinguishable from CCAM preoperatively. A high index of suspicion for PPB must be considered in any child presenting with cystic lung lesions beyond early infancy, particularly in a child with poor weight gain.
authors.affiliation: The Hospital for Sick Children, Division of General and Thoracic Surgery, Toronto, Canada.
authors.forename: C
authors.initials: C
authors.lastname: Oliveira
authors.forename: S
authors.initials: S
authors.lastname: Himidan
authors.forename: A C
authors.initials: AC
authors.lastname: Pastor
authors.forename: A
authors.initials: A
authors.lastname: Nasr
authors.forename: D
authors.initials: D
authors.lastname: Manson
authors.forename: G
authors.initials: G
authors.lastname: Taylor
authors.forename: N L
authors.initials: NL
authors.lastname: Yanchar
authors.forename: G
authors.initials: G
authors.lastname: Brisseau
authors.forename: P C W
authors.initials: PC
authors.lastname: Kim
mesh_terms: D002675:Child, Preschool; D015615:Cystic Adenomatoid Malformation of Lung, Congenital / Q000000981:diagnostic imaging*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007223:Infant; D008175:Lung Neoplasms / Q000000981:diagnostic imaging*; D008297:Male; D057234:Preoperative Period; D018202:Pulmonary Blastoma / Q000000981:diagnostic imaging; D011859:Radiography; D012189:Retrospective Studies