Yellow Nail Syndrome in Which Intranodal Lymphangiography Contributed to the Diagnosis

Yellow nail syndrome (YNS) is a rare disease comprising the clinical triad of yellow nail discoloration, pleural effusion, and lower limb lymphedema. We encountered a difficult-to-treat case of YNS in which the diagnosis was finally made based on intranodal lymphangiography. An 84-year-old man was admitted to our hospital with pleural effusion and yellow-green discoloration of the nails, accompanied by onychomycosis and limb lymphedema. Intranodal lymphangiography revealed a slow contrast flow and narrowing of the thoracic duct, suggesting lymphatic duct dysplasia and leading to the diagnosis of YNS.