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.
Materials & 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.
Conclusion: 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.
Key words
pulmonary blastoma - congenital cystic adenomatoid malformation - lung - cancer -
child
References
Correspondence
peter.kim@sickkids.ca
