Imaging of central lymphatic abnormalities in Noonan syndrome.

BACKGROUND

Children with Noonan syndrome are known to have increased risk for lymphatic disorders, the extent and nature of which are poorly understood.

OBJECTIVE

Our objective was to describe the imaging findings of the central lymphatic abnormalities in children with Noonan syndrome who underwent central lymphatic imaging.

MATERIALS AND METHODS

We conducted a single-center retrospective review of all children with a confirmed history of Noonan syndrome who presented for lymphatic imaging over a 5-year period. Imaging evaluation was performed on unenhanced T2-weighted (T2-W) imaging, dynamic-contrast MR lymphangiography or conventional lymphangiography. Two readers evaluated the imaging in consensus for the distribution of fluid on T2-W imaging and for lymphatic flow of intranodal contrast agent and thoracic duct abnormalities on dynamic-contrast MR lymphangiography and conventional lymphangiography. We performed a chart review for clinical history and outcomes.

RESULTS

We identified a total of 10 children, all but one of whom had congenital heart disease. Presenting symptoms included chylothorax (n=9) and ascites (n=1). Nine had T2-W imaging, seven had dynamic-contrast MR lymphangiography, and seven had conventional lymphangiography. All with T2-W imaging had pleural effusions. On both dynamic-contrast MR lymphangiography and conventional lymphangiography, perfusion to the lung was seen (n=6), with intercostal flow also seen on dynamic-contrast MR lymphangiography (n=6). The thoracic duct was not present in three children and the central thoracic duct was not present in three. A double thoracic duct was seen in two children.

CONCLUSION

Children with Noonan syndrome and clinical evidence of lymphatic dysfunction have central lymphatic abnormalities characterized by retrograde intercostal flow, pulmonary lymphatic perfusion, and thoracic duct abnormalities.