Massive compensatory hyperinflation.

To cite: Madan K, Singh N. BMJ Case Rep Published online: [please include Day Month Year] doi:10.1136/ bcr-2013-008668 DESCRIPTION A 14-year-old girl presented with a 1-year history of insidious onset dyspnoea. Three years previously, she had been treated for 6 months with directly observed antituberculous treatment for sputum smear positive pulmonary tuberculosis (TB) and the treatment was successful. Chest radiograph demonstrated gross mediastinal shift to the right side with hyperinflated left hemithorax (figure 1). A CT scan demonstrated massive hyperinflation and anterior herniation of left lung across the midline to the right side with complete right lung collapse (figure 2). Flexible bronchoscopy demonstrated tight cicatricial stenosis of the right main bronchus. A diagnosis was made of massive compensatory hyperinflation of the left lung secondary to post-tubercular right main bronchus stenosis and destroyed right lung. Flexible bronchoscopic balloon dilation of right main bronchus was unsuccessful owing to the extremely tight nature of the stenosis. As the patient had symptoms only on more than usual levels of exertion, she was reassured and advised for periodic follow-up. Massive compensatory unilateral pulmonary hyperinflation (also described as pseudohorseshoe lung) is a consequence to a number of conditions leading to contralateral lung volume loss. In our patient, tuberculous lung parenchymal and endobronchial involvement led to slowly progressive bronchostenosis and extensive right lung volume loss accompanied by simultaneous progressive hyperinflation of left lung. Such degrees of extensive unilateral lung destruction are often seen with TB. On the other hand, true horseshoe lung is a rare congenital anomaly in which the bases of the right and the left lungs are fused together by a narrow isthmus posterior to the cardiac apex.