[A rare combination: an azygos lobe and an abnormality of bronchial implantation].

The case of a 5 month old female infant with respiratory problems since birth in the form of a recurrent right pneumonia, associated with slight pulmonary arterial hypertension. Persistence of a paramediastinal opacity suggestive of a right upper lobe atelectasis led to bronchography being performed which revealed a bronchus implanted into the right side of the trachea. At operation there were two abnormalities: --an azygos lobe represented by the apical segment of the right upper lobe; --a tracheal bronchus, apical segmental apical, ventilating this territory. Simple disenclavement of the parenchyla and pleuroplasty led to regression of the respiratory disturbances. The special feature of the case lay in the rarity of an azygos lobe ventilated by a tracheal bronchus. The azygos lobe results from an abnormality in the topography of the arch of the azygos vein which draws the parietal pleura with it, forming a mesoazygos. It is not a supernumary lobe. Abnormalities of bronchial implantation are located above all along the right side of the trachea (tracheal bronchi) and correspond in most instances to ectopic positioning of a segmental bronchus of the upper lobe, as in the present case.