An unusual cause of right upper zone opacity − azygous fissure

Abstract

Azygous lobe is a normal congenital anatomic variant of the right upper lobe. The azygos lobe is not anatomically a separate lobe. Radiologically azygous lobe is noted in the apicomedial region of the right lung and is separated from the rest of upperlobe by azygous fissure. Though not a pathology, azygous lobe can be mistaken for a lung abscess or a bulla. Other complications include hemoptysis or azygous vein aneurysm.