Azygos lobe

We report the case of a 25-year-old male who consult for a chronic dry cough without fever or medical history, in front of that we perform a chest X-ray completed by a chest-CT who shows a thin curvilinear density seen in the upper right lung, convex towards the chest wall at its base is the azygos vein which can be seen as a teardrop-shaped structure (A,B,C,D). The azygos lobe or fissure is a rare anatomic variant affecting about 1% of the general population. He is a summery lobe without pathological consequence on the breathing function, who form when posterior cardinal vein penetrates the upper medial portion of the apical segment of the right upper lobe, instead of remaining along the apex of the lung. This demarcating fissure contains both visceral and parietal pleural layers and has no bronchus, so is not a true accessory lobe with a variable size. The diagnosis is made incidentally and easily by chest X-ray or CT and does not require any treatment.