An autopsy case report of yellow nail syndrome coincided with primary biliary cholangitis.

Yellow nail syndrome (YNS) is a rare entity characterized by thickened yellowish nails, lymphedema and respiratory manifestations such as pleural effusion. Lymphatic dysfunction is considered as a cause of YNS. However, evidence of systemic dilatation/hyperplasia of lymphatics based on autopsy in YNS is not available. In this report, autopsy revealed dilatation and hyperplasia of lymphatic vessels in lungs, visceral and parietal pleurae, and intestines. We identified the direct opening of lymphatic vessels of the visceral pleura to the pleural cavity, which indicated the pathophysiology of uncontrollable pleural effusion in YNS. The current case was compromised with primary biliary cholangitis (PBC). The onset of PBC seemed to be related with the progression of YNS.