Pleuropulmonary blastoma

Diagnosis

Pleuropulmonary blastoma

History

Thirty months old young girl with large right chest mass.

Findings

There is a large mass occupying most of the right chest cavity and displacing mediastinal structures to the left. There is heterogeneous FDG avidity depending of the lesion’s density. Cystic components are hypoactive while solid parts are highly FDG-avid. SUV max is 9.9 in the posteromedial aspect of the lesion.

No other suspicious lesion.

DDx

Pleuropulmonary blastoma

Neuroblastoma

Ewing’s sarcoma

PNET

Rhabdomysarcoma

Discussion

Pleuropulmonary blastoma (PPB) is a rare intrathoracic malignant neoplasm occuring in early childhood, most cases occuring before six years old. This tumour is associated with mutation of the DICER1 gene.

There are three types of PPB. Type I is purely cystic. Type II is composed of cystic and solid areas, whereas type III is a solid tumor without cystic spaces. Type I tumors occur in younger children than type II/III, with a median age around 1 year old. It is also known that type I can progress to more aggressive type II or III. The type of PPB is a strong predictor of outcome. Type I has the better prognosis and type III the worst. The presence of distant metastasis at diagnosis is another poor prognostic factor.

Naffaa et al. described CT findings in four patients with PPB. They reported large masses with complete or near-complete opacification of the hemithorax and  heterogeneous low attenuation. There was associated pleural effusion but absence of chest wall invasion. All tumors were on the right side. In another study, Priest et al. reported that 70% of PPBs were located in the right hemithorax.

To our knowledge, there is only one report of FDG PET/CT in the context of PPB. Geiger et al. used the FDG PET/CT to assess response to neoadjuvant chemotherapy and decide the timing of surgery, facilitating tumor resection.

References

Manivel et al : Pleuropulmonary blastoma. The so-called pulmonary blastoma of childhood. Cancer. 1988 Oct 15;62(8):1516-26.

Priest et al : Pleuropulmonary blastoma: a clinicopathologic study of 50 cases. Cancer. 1997 Jul 1;80(1):147-61

Romeo et al : Pleuropulmonary blastoma: long-term survival and literature review. Med Pediatr Oncol. 1999 Oct;33(4):372-6

Lallier et al : Pleuropulmonary blastoma: a rare pathology with an even rarer presentation. J Pediatr Surg. 1999 Jul;34(7):1057-9

Perdikogianni et al : Pleuropulmonary blastoma: an aggressive intrathoracic neoplasm of childhood. Pediatr Hematol Oncol. 2001 Jun;18(4):259-66

Naffaa et al : Imaging findings in pleuropulmonary blastoma. Pediatr Radiol. 2005 Apr;35(4):387-91

Geiger et al : In Vivo. Imaging findings in a 3-year-old girl with type III pleuropulmonary blastoma. 2007 Nov-Dec;21(6):1119-22

Yu et al : Primary lung tumors in children and adolescents: a 90-year experience. J Pediatr Surg. 2010 Jun;45(6):1090-5

Messinger et al : 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

Bisogno et al : Treatment and prognostic factors in pleuropulmonary blastoma: an EXPeRT report. Eur J Cancer. 2014 Jan;50(1):178-84

Priest et al : Pulmonary cysts in early childhood and the risk of malignancy. Pediatr Pulmonol. 2009 Jan;44(1):14-30