Atypical course of the azygos vein and its tributaries - case report.

During standard anatomical dissection an atypical course of the azygos vein was found. In the present case, the azygos vein was formed by the subcostal and lumbar veins at the level of the 11th vertebra and to the left of the midline. Initially maintaining its left-sided position, it gradually shifts to the right, heading toward the superior vena cava. In the presented case, a large venous vessel, with a width reaching up to 9 mm serves as the sole independent outlet for the right and left posterior intercostal veins. An atypical course of venous structures may be clinically significant, especially for thoracic surgeons, and knowledge about morphological variations in that region is very important.