Imaging description

A three-year-old previously healthy male presented with 1 week of progressive respiratory distress, fever, and lethargy. He was being treated for a viral upper respiratory tract infection.

The frontal chest radiograph (Fig. 12.1a) shows complete opacification of the left hemithorax with marked tracheal and mediastinal shift to the right and compressive atelectasis of the right lung. The differential diagnosis includes a large left pleural effusion, which could be related to infection/pneumonia/empyema, versus a large mediastinal or intrapulmonary mass such as lymphangioma, teratoma, neuroblastoma, pleuropulmonary blastoma, or lymphoma.

Axial contrast-enhanced CT (Fig. 12.1b) and coronal reformat (Fig. 12.1c) show a large hypodense heterogeneous largely intrapulmonary mass with irregular enhancing areas, causing mediastinal shift and inversion of the left hemidiaphragm. It was uncertain whether the mass was partially cystic or if there was some component of pleural effusion. The mass did not extend behind the aorta or encase the mediastinal vessels, making a diagnosis of a primary mediastinal mass such as neuroblastoma or lymphoma less likely.

Ultrasound of the chest (longitudinal view) revealed a largely solid lesion with heterogeneous echogenicity with some cystic components (Fig. 12.1d). There was no evidence of pleural effusion.

Based on imaging this was thought to be a large cystic/solid intrapulmonary neoplasm with pleuropulmonary blastoma the most likely diagnosis in a child of this age. Subsequent biopsy of the lesion confirmed a type II pleuropulmonary blastoma.