Review of the Paediatric Pleuropulmonary Blastoma French Series

Pleuropulmonary blastoma is a rare embryonic malignant tumour that remains the most frequent malignant tumour of the lung in childhood. The International Pleuro pulmonary Blastoma Registry (IPPB) found only 220 cases in 2009 and 350 in 2015. In France, 20 cases were identified in 2009.

Three histologies are described: type 1 purely cystic, type 2 combined and type 3 solid. Median age at diagnostic is 12 months, 35 months and 41 months respectively. Evolution is possible from type 1 to type 2 or 3 in 10% of the cases.

Since 2009, DICER 1 mutations research is proposed systematically to all families.

PPB symptoms are usually non-specific. Diagnostic is evoked when imaging work up shows bubbles or solid lesions, and confirmed by pathological analysis. However the diagnosis can be difficult because of the proximity with congenital cystic adenomatoid malformation.

The French society of paediatric oncology recommends surgery at first instance. PPB type 1 remains a problem because some are still misdiagnosed as CCAM, a benign lesion. Chemotherapy depends on the PPB type and the quality of the resection. There is a real interest to analyse the French series.

The prognosis of type 2 and 3 is low with a 5 years survival rate of 45-60%, whereas type 1 survival rate is 91%. The French experience reports a 100% survival rate in type 1 and 48% in type 2 and 3. Other prognostic factors are initial size of the tumour, extra pulmonary invasion and quality of surgery.

Early local relapses are possible and late ones concern more often type 2 and 3 with more cerebral metastasis.

In 2009, the french cases were collected, but no update has been performed since. The aim of this retrospective review of the cases since 2000, is to audit the care of PPB patients in France and update the French rare tumour database.

Evoking PPB diagnosis is difficult when imaging shows a neonatal cystic lesion. There are no radiologic criteria in the literature that differentiate congenital pulmonary cystic lesion and PPB type 1. Radiological presentation is however overlapping. Another aim of this study will be to look for a predictive sign of type 1 PPB.