From the Research
An incidental azygos fissure on a chest X-ray requires no treatment as it is a normal anatomical variant present in about 1% of the population. This finding represents an invagination of the visceral and parietal pleura containing the azygos vein, typically appearing as a fine, curved line in the right upper lung zone that extends from the apex toward the hilum. The azygos fissure forms during embryological development when the azygos vein fails to migrate to its normal position at the tracheobronchial angle 1. While it may initially be mistaken for pathology by inexperienced observers, recognizing this variant is important to avoid unnecessary investigations or interventions. Radiologists and clinicians should document this finding in the patient's record but reassure patients that it has no clinical significance, causes no symptoms, and requires no follow-up. The presence of an azygos fissure may occasionally serve as a useful anatomical landmark during thoracic surgery but otherwise has no impact on patient management or prognosis.
Some key points to consider:
- The azygos fissure is a rare congenital variant of the right lung, usually diagnosed as an incidental finding 2.
- The azygos vein might be confused with pathological conditions and might also be associated with lung cancers, pneumothorax, and congenital abnormalities 1.
- Knowledge about the azygos vein is significant for surgeons, because it might reduce iatrogenic damage and help them avoid unexpected bleeding during thoracic surgery 1.
- Despite the fact that the azygos lobe is a well-known variant, dissemination of knowledge about it is still inadequate 1.
In terms of treatment, no specific treatment is required for an incidental azygos fissure, as it is a benign anatomical variant. However, it is essential to recognize this variant to avoid unnecessary investigations or interventions. The patient should be reassured that the finding has no clinical significance and does not require follow-up.