Novel clinical phenotype of generalised lymphatic dysplasia in a neonate: a missed diagnosis.

We report a preterm neonate who had a large cervical cystic hygroma and right chylothorax. She was operated on day-21 and a near-complete resection of cystic hygroma was done. She developed refractory hypoxemia and shock post surgery and died after 24 hours. During autopsy, the chest cavity was found to be filled with chyle. Histopathological examination showed dilated lymphatics in the pleura, hepatic capsule, serosa of stomach and intestines, peri-pancreatic regions, peri-renal capsule and peri-adrenal tissues suggestive of generalised lymphatic dysplasia. Clinical exome sequencing did not reveal any pathogenic mutation in the genes involved in primary lymphatic dysplasia, noonan syndrome or rasopathies.