The left supraclavicular nodes are the classical Virchow's node because they receive lymphatic drainage of most of the body (from the thoracic duct) and enters the venous circulation via the left subclavian vein.
The left supraclavicular nodes, which are referred to as Virchow's node, collect lymphatic fluid from various parts of the body (through the thoracic duct) and subsequently enter the venous circulation via the left subclavian vein.