A 70-year-old woman presented to the emergency department with symptoms of a lower respiratory infection. A chest x-ray showed enlargement of the mediastinal space. The patient was admitted with a respiratory tract infection and started on antibiotic treatment. A computed tomography (CT) scan of the thorax revealed a large diaphragmatic hernia with stomach, large intestine and caudal pancreas lodged in the thoracic cavity. After the antibiotic treatment, the patient became asymptomatic and surgery repair was declined.

Yellow Nail Syndrome (YNS) is a rare, and probably misdiagnosed, condition. It must be considered in middle-aged patients with unexplained chronic respiratory manifestations, lymphedema and nail abnormalities. We present two cases of undiagnosed YNS until the current admissions, despite several years of investigation. The authors wish to draw attention to this syndrome, of which diagnosis is clinical and of exclusion. LEARNING POINTS• Yellow nail syndrome is characterized by abnormal nails, lymphedema and respiratory manifestation.• Diagnosis is clinical and should raise the suspicion of underlying medical conditions. The treatment is symptomatic.