Lumbar azygos vein producing an azygos lobe in the right lung.

The continuation of the azygos vein with the inferior vena cava and a well demarcated azygos lobe of the right lung were detected during routine dissection of a 65-years-old white male cadaver. The azygos arch was found dilated and malpositioned to create an aberrant azygos fissure in the right superior lobe which, was occupied by a fold of parietal pleura. The developmental and clinical significance of the azygos lobe is discussed.