Pleuropulmonary blastoma: a report on 350 central pathology-confirmed pleuropulmonary blastoma cases by the International Pleuropulmonary Blastoma Registry

Cancer. 2015 Jan 15;121(2):276-85. doi: 10.1002/cncr.29032. Epub 2014 Sep 10.


Background: Pleuropulmonary blastoma (PPB) has 3 subtypes on a tumor progression pathway ranging from type I (cystic) to type II (cystic/solid) and type III (completely solid). A germline mutation in DICER1 is the genetic cause in the majority of PPB cases.

Methods: Patients confirmed to have PPB by central pathology review were included, and their clinical characteristics and outcomes were reported. Germline DICER1 mutations were sought with Sanger sequencing.

Results: There were 435 cases, and a central review confirmed 350 cases to be PPB; 85 cases (20%) were another entity. Thirty-three percent of the 350 PPB cases were type I or type I regressed (type Ir), 35% were type II, and 32% were type III or type II/III. The median ages at diagnosis for type I, type II, and type III patients were 8, 35, and 41 months, respectively. The 5-year overall survival (OS) rate for type I/Ir patients was 91%; all deaths in this group were due to progression to type II or III. OS was significantly better for type II versus type III (P = .0061); the 5-year OS rates were 71% and 53%, respectively. Disease-free survival (DFS) was also significantly better for type II versus type III (P = .0002); the 5-year DFS rates were 59% and 37%, respectively. The PPB type was the strongest predictor of outcome. Metastatic disease at the diagnosis of types II and III was also an independent unfavorable prognostic factor. Sixty-six percent of the 97 patients tested had a heterozygous germline DICER1 mutation. In this subset, the DICER1 germline mutation status was not related to the outcome.

Conclusions: Cystic type I/Ir PPB has a better prognosis than type II, and type II has a better outcome than type III. Surveillance of DICER1 carriers may allow the earlier detection of cystic PPB before its progression to type II or III PPB and thereby improve outcomes.

Keywords: DICER1; childhood cancer; pleuropulmonary blastoma; rare cancer.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Child
  • Child, Preschool
  • DEAD-box RNA Helicases / genetics*
  • Disease Progression
  • Disease-Free Survival
  • Female
  • Germ-Line Mutation*
  • Humans
  • Infant
  • International Cooperation
  • Kaplan-Meier Estimate
  • Lung Neoplasms / complications
  • Lung Neoplasms / mortality
  • Lung Neoplasms / pathology*
  • Male
  • Pleural Neoplasms / complications
  • Pleural Neoplasms / mortality
  • Pleural Neoplasms / pathology*
  • Proportional Hazards Models
  • Pulmonary Blastoma / complications
  • Pulmonary Blastoma / mortality
  • Pulmonary Blastoma / pathology*
  • Registries
  • Ribonuclease III / genetics*
  • United States / epidemiology
  • Young Adult


  • DICER1 protein, human
  • Ribonuclease III
  • DEAD-box RNA Helicases

Supplementary concepts

  • Pleuropulmonary blastoma