Paediatric mediastinal masses are the most common chest masses in children, with the anterior mediastinum being the most common site 1.
As in adults, mediastinal masses are classified depending on anatomical sites:
anterior mediastinal masses
middle mediastinal masses
posterior mediastinal masses
Anterior mediastinal masses
Basic approach to these lesions is by chest radiograph (PA and lateral) for localisation followed by contrast-enhanced CT for characterisation:
malignant lymphoma (Hodgkin and non-Hodgkin) - most common
teratoma - common
thymus (benign enlargement) - common
thyroid (retro- or substernal extension)
angioma
mesenchymal tumours
lymphangioma (cystic hygroma) - generally extends from neck into mediastinum
Middle mediastinal masses
Basic approach to these lesions is by chest radiograph (PA and lateral) for localisation, with barium swallow to identify areas of compression followed by contrast-enhanced CT for characterisation:
foregut duplication cyst (bronchogenic, enteric, and neuroenteric) - most common; bronchogenic cyst is more common
vascular malformations
Posterior mediastinal masses
Basic approach to these lesions is by chest radiograph (PA and lateral) for localisation followed by MRI for evaluation of intraspinal extension of neurogenic tumours and distinction between vascular structures and soft tissues. Contrast-enhanced CT can be carried out when MRI is not available:
neurogenic tumour - most common
vascular malformations