A patient presents with chest pain due to aspiration pneumonitis. On examination there is dullness on percussion in area medial to the medial border of scapula on elevation of arm. Which pa of the lung is most likely to be affected?

Upon elevation of arm, medial border of scapula corresponds to the oblique fissure of lung on the posterior thorax. Medial to that lies the apex of lower lobe of the lung. This is the location of the apical (superior) BPS of right lower lobe, which is a common site of aspiration pneumonitis. As right primary bronchus is shoer in length , has wider lumen , is more veical hence more prone for aspiration and leading to aspiration pneumonitis