Some further investigation of the large airways is required. The great majority of symp-
tomatic lung tumours are visible on plain chest X-ray but central lesions in large airways
may not be seen. Further investigation could be a bronchoscopy or a computed tomog-
raphy (CT) scan. A bronchoscopy to see and biopsy any lesion would be best. In this case,
fibre-optic bronchoscopy showed a carcinoma in the lower trachea reducing the lumen to
a small orifice. Treatment was by radiotherapy with oral steroids to cover any initial
swelling of the tumour which might increase the degree of obstruction in the trachea.
- Large-airway narrowing produces characteristic findings on visual displays of respiratory
function but is more difficult to identify from the numbers alone. - A small proportion of central lung tumours may present with local symptoms but a nor-
mal chest X-ray.