ABSTRACT
Answer 2 The majority of bronchial carcinomas develop as masses in the proximal bronchi, near to the hila of the lungs. As with other tubular structures and organs in the body, if a tumour develops, either from the mucosal lining of the tube or from the deeper tissues of the wall, the tube may become partially or completely obstructed by the neoplasm. Narrowing of a bronchus impedes air flow in and out of the part of the lung distal to that airway. If the volume of lung affected is sufficiently great, this can manifest as dyspnoea, especially in a patient who has COPD and therefore has decreased lung function anyway. In extreme cases, the obstruction is complete and causes collapse of the affected part of the lung. The findings in this patient on presentation suggested an element of collapse.
