An autopsy case of azygos lobe and the extra-pulmonary course of the bronchial veins in man.

The present case represents the second report of an aberrant azygos lobe, following Adachi's (1940) first case. The authors describe the characteristic features of an azygos lobe observed in the right lung of a 65-year-old man as well as the extra-pulmonary course of the bronchial arteries and veins. The literature on the azygos lobe reported in Japan and the extremely rare cases in which an azygos lobe has been found on the left side, are summarized. Upon dissecting the pulmonary parenchyma, it became clear that the azygos lobe was supplied by definitive segmental branches (B1a and B2a, A1a and A2a, and V1a and V2a) of the tracheobronchial tree and pulmonary vessels. The authors review and summarize the patterns of the segmental bronchi and vessels in the azygos lobe and also discuss the development of this anomaly.