Recurrent congenital pulmonary lymphangiectasia

A homozygous variant in growth and differentiation factor 2 (GDF2) may cause lymphatic dysplasia with hydrothorax and nonimmune hydrops fetalis

The etiology of nonimmune hydrops fetalis is extensive and includes genetic disorders. We describe a term-born female neonate with late onset extensive nonimmune hydrops, that is, polyhydramnios, edema, and congenital bilateral chylothorax. This newborn was successfully treated with repetitive thoracocentesis, total parenteral feeding, octreotide intravenously and finally surgical pleurodesis and corticosteroids. A genetic cause seemed plausible as the maternal history revealed a fatal nonimmune hydrops fetalis. A homozygous truncating variant in GDF2 (c.451C>T, p.(Arg151*)) was detected with exome sequencing. Genetic analysis of tissue obtained from the deceased fetal sibling revealed the same homozygous variant. The parents and two healthy siblings were heterozygous for the GDF2 variant. Skin and lung biopsies in the index patient, as well as the revised lung biopsy of the deceased fetal sibling, showed lymphatic dysplasia and lymphangiectasia. To the best of our knowledge, this is the first report of an association between a homozygous variant in GDF2 with lymphatic dysplasia, hydrothorax and nonimmune hydrops fetalis.

Congenital pulmonary lymphangiectasia

Congenital pulmonary lymphangiectasia (CPL) is a rare but fatal disease, usually having an onset from the first few hours to days after birth. Inconsistent nomenclatures were used for CPL in the past decades. Patients often present with intractable respiratory failure, hydrops fetalis and even sudden death. The etiologies of CPL remain unclear. Previous hypotheses suggested that CPL might be caused by conditions preventing normal regression of the lymphatics after the 18th-20th week of gestation. Up-to-date biological studies on lymphatic development, lymphatic valve formation and occurrence of hydrops fetalis revealed possible causative relations with mutations of genes of the vascular endothelial growth factor receptor (VEGFR), RAS/MAPK, PI3K/AKT and NF-κB signaling pathways. Lung biopsy with subsequent histological and immunohistochemical studies is a gold standard of CPL diagnosis. Apart from symptomatic and supportive treatments, novel regimens including sirolimus, a mammalian target of rapamycin (mTOR) inhibitor, one of the inhibitors of the pertinent signaling pathways and ethiodized oil lymphatic embolization under ultrasound-guided intranodal lymphangiography have shown encouraging short-term therapeutic effects for lymphatic anomalies. Surgical operations (lobectomy or pneumonectomy) can be the treatment of choice for patients with CPL confined to one lobe or one lung. Patients with CPL usually have a poor prognosis and often die during the neonatal period. Their prognoses are expected to improve with the development of modern therapeutic agents.

Congenital pulmonary lymphangiectasis

Congenital pulmonary lymphangiectasis (CPL) is a rare vascular malformation causing dilated lymph vessels and disturbed drainage of lymph fluid. Based on the pathogenesis and clinical phenotype it can be classified as primary or secondary CPL. Associated genetic syndromes with or without lymphedema, familial occurrence and gene mutations have been described. In utero, it may present as non-immune hydrops with pleural effusions. At birth neonates may have respiratory failure due to chylothorax and pulmonary hypoplasia, causing very high short term mortality rates. Other cases may become symptomatic any time later in childhood or even during adult life. CPL is usually diagnosed based on the combination of clinical signs, imaging and histological findings. Open-lung biopsy is considered the gold standard for the diagnosis of CPL. Treatment is primarily supportive featuring aggressive mechanical ventilation and the management of problems associated with congenital chylothorax including chest-drainage, medium-chain triglycerides (MCT) diet, and octreotide.