Congenital anomalies of respiratory system are quite diverse and not all of them are subject to surgical treatment. One example is accessory lobe of the azygos vein. This anomaly usually has no clinical manifestations and requires only follow-up, as well as attention in surgery on the right half of the chest for some other disease. This situation changes when complications occur, for example, purulent-inflammatory process. Therapy is not always effective, and lung tissue destruction requires surgical treatment. Progressive destruction complicates diagnosis and choosing surgical tactics. We present a rare case of severe purulent-inflammatory complication with abscess in accessory lobe of v. azygos. Anatomical abnormalities following this congenital pulmonary anomaly can cause difficulties in surgeries for other intra-thoracic diseases. The situation is especially relevant for thoracoscopic access. This report will be useful for radiologists, pulmonologists and thoracic surgeons.