Middle Lobe Syndrome

Abstract

Middle lobe syndrome (MLS) commonly presents with chronic cough, right-sided chest pain, purulent sputum, hemoptysis, weight loss, and pneumonia. The etiology of MLS was initially described as external compression of the right middle lobe bronchus. However, it is known that multiple etiologies of MLS exist, involving intrinsic and extrinsic bronchial compression. The etiologies include broncholithiasis, peribronchial lymphadenopathy, foreign body aspiration, and bronchiectasis. The presenting complaints of MLS are similar regardless of the etiology, referable to the common factor of obstruction of the right middle lobe.Lateral chest radiography in MLS characteristically demonstrates a wedge-shaped opacity in the right middle lobe. We present a case of a 38-year-old Korean female with a remote medical history significant for pulmonary tuberculosis, who presented for evaluation of an enlarging right hilar mass with associated productive cough, chills, night sweats, right-sided pleuritic chest pain, weight loss, and fever. She was diagnosed with MLS, which was successfully managed surgically with a middle lobe lobectomy with complete resolution of symptoms.