Tuberculosis of the Rare Azygos Lobe of Lung

Abstract Background: The azygos lobe is a rare anatomical variant seen in the upper lobe of right lung. It occurs during embryological development due to the failure of posterior cardinal vein to migrate supero-medially. It is often an incidental finding on imaging and is asymptomatic in majority of cases. Tuberculosis involving the azygos lobe is extremely rare. Only a few cases of tuberculosis involving the azygos lobe have been reported in literature.Case presentation: We present a rare case report of tuberculosis infection involving the azygos lobe in a 57-year-old Indian male with history of chronic cough, fever, haemoptysis and weight loss.Conclusions: The azygos lobe is usually asymptomatic, but it may be misdiagnosed as bulla, lung cyst or abscess. In rare cases it may be associated with certain pathology such as tuberculosis, other infections, and lung cancer. Hence, it is pertinent for a radiologist to be aware of this variant when reporting chest imaging cases.