title: Pitfalls to avoid: a chest mass in a tachypneic child.
abstract: A mass adjacent to the right upper mediastinum in an asymptomatic seven-week-old girl displacing the upper lobe segmental bronchi was considered to be a normal thymus. The mass regressed over the next two years. The child is clinically and radiologically normal at age seven years.
mesh_terms: D005260:Female; D006801:Humans; D007223:Infant; D008482:Mediastinum / Q000000981:diagnostic imaging; D011859:Radiography; D012119:Respiration; D013950:Thymus Gland / Q000002:abnormalities / Q000000981:diagnostic imaging*