Chylous pleural and peritoneal effusions in neonates is a challenging disorder and requires a high index of suspicion for timely diagnosis and management. Neonatal chylous effusions can be isolated chylothorax, traumatic chylothorax, pulmonary lymphangiectasia, central lymphatic flow disorder/ generalized lymphatic anomaly presenting with chylous ascites, pleural effusions and soft tissue edema. The central lymphatic flow disorders are associated with greater mortality risk as compared to isolated chylothorax [1].

Recent improvement in lymphatic imaging techniques, such as intranodal contrast lymphangiography and intranodal Gadolinium-enhanced MR lymphangiography has led to better understanding of the pathophysiological mechanisms of the Neonatal lymphatic flow disorder (NLFD) by delineating the detailed anatomy and flow dynamics of the central lymphatic system; thereby permitting targeted therapeutic interventions in neonates.

It is imperative to know the clinical presentation patterns and management options of the NLFD and recently Toptan et al. have described the same for two major groups of neonatal chylothorax in thirteen infants [2]. They have emphasized on the multidisciplinary approach for the management of such cases and found that up to 66.6% of the infants responded to medium chain triglycerides (MCT) and complete resolution was noted in 85.7% of the responders. Complete resolution of chylothorax fluid was observed in 7 (77.7%) of nine patients who responded to octreotide treatment as well.

Although the study did not focus on the imaging assessment of the patients, it is worth noting that the anatomical delineation of the lymphatic disorders using dynamic contrast enhanced MR lymphangiography (DCMRL) in such cases would help in distinguishing the various patterns of neonatal chylous effusions. A study by Pinto et al. had utilized the DCMRL in 35 neonates to understand the classification of the disorders as well as impact of minimally invasive embolization techniques on outcomes [1]. They found that 34 patients (97.1%) had pleural effusions. None of the neonatal chylothorax group had ascites, edema or dermal backflow compared to patients with central lymphatic flow disorder group. MRI depicted abnormal flow of contrast towards pulmonary lymphatics in patients with neonatal chylothorax, a condition termed as pulmonary lymphatic perfusion syndrome (PLPS). In addition, 73.3% of the neonatal chylothorax group of patients had undergone ethiodized oil embolization with complete resolution of pleural effusions achieved in all infants of this group. However, complete resolution of effusions was seen in only 26.7% patients who received conservative therapy. In addition, in 45% of central lymphatic flow disorder (CLFD) patients, resolution of chylothorax was achieved with some form of therapy (intervention or conservative).

In another study by Biko et al. they had tried to compare similar features identified on post-natal MR lymphangiography (MRL) with antenatal MRI findings in the fetus [3]. They found that the presence of nutmeg lung, and those with lymphatic flow to the lungs only were classified as neonatal chylothorax. The presence of dermal backflow and perfusion to the lungs were described as central lymphatic flow disorder. There was resolution of pleural effusion in two patients of neonatal chylothorax treated with lymphatic intervention using an oil-based contrast agent (Lipiodol, Guerbet, Bloomington, Indiana, USA) in their series of five cases.

A recent review by Rabinowitz et al. focused on the role of DCMRL and lymphatic interventions in classification and targeted therapy in these two disorders of neonatal chylous effusions [4]. Oil-based contrast (lipiodol) embolization is effective in treatment of isolated neonatal chylothorax. Surgical thoracic duct-venous anastomosis can be done for CLFD secondary to obstruction of the thoraco-venous junction. New systemic therapies using rapamycin inhibitors are also being recently described for CLFD caused by elevated central pressure and/or thoracic duct dysplasia.

It is worth noting that the advances in imaging and interventional radiology herald an exciting scope for treatment of neonatal chylothorax with minimally invasive techniques. The study by Toptan et al. and others have paved a pathway for future studies in effective management of such neonatal lymphatic disorders.