Table 4 Pulmonary Lymphangiectasia: diagnostic work-up

Chest x-ray

Hyperinflation with interstitial markings

Radiological findings in PL may improve over time. Longitudinal follow-up pointed to the possible progression of hazy infiltrates, that are usually seen during the neonatal period, to a more perihilar interstitial pattern with varying degrees of lung inflation

High Resolution Computed Tomography (HRCT)

Diffuse thickening of the interstitium, both of the peribronchovascular interstitium and the septa surrounding the lobules

HRCT is the technique of choice for diagnosing PL

Magnetic Resonance Imaging (MRI)

Coronal MRI T1 may permit to show thickening of the interstitium, pleural fluid effusion, and atelectasia. Axial MRI T2 usually shows high-signal material within the pulmonary interstitium, which is very often associated with pleural effusion.

HRCT is better than MRI not only in diagnosing PL, but, more in geeral, for the diagnosis of pediatric interstitial lung disease.

Lung biopsy

Useful for demonstrating the presence of dilated lymphatic spaces in the sub-pleural connective tissue, along thickened interlobar septa, and around bronchovascular axes

Great caution must be taken when preparing histological specimens and when interpreting lung biopsies or autopy samples

Lymphoscintigraphy

Useful for evaluating lung lymph vessel involvement by showing radiotracer accumulation in the lung and by providing evidence of back-flow within the thoracic duct

It provides valuable morpho-functional information regarding the lymphatic system

Bronchoscopic evaluation and lung function tests

Not specific

They may be useful for ruling out other pulmonary pathologies and for carrying out bronchial lavage in order to identify and isolate respiratory pathogens