Anomalous azygos venous system in a south Indian cadaver: a case report.

Introduction: The posterior thoracic wall, an area drained by the azygos venous system, is a common site for surgical intervention. Since the venous part of the cardiovascular system is subject to most common variation, abnormalities in the azygos venous system are often reported.
Case Presentation: During routine dissection classes for undergraduate medical students, we encountered a variation in the azygos venous system in a 65 years old south Indian male cadaver. We observed that there was no accessory azygos vein, and left 4th, 5th, 6th and 7th posterior intercostal veins terminated directly into azygos vein.
Conclusion: Identifying these types of variations is important during imaging this region and surgical operations of mediastinum.