Intercostal lymph nodes

The intercostal lymph nodes, also termed the posterior intercostal nodes as the internal thoracic group effectively forms an anterior intercostal group, drain the lymphatic territory of:

• posterior thoracic cavity around the respective intercostal space
• parietal pleura deep to the intercostal space

Individual nodes on each side are sited just lateral to the head of the respective rib, deep to the innermost intercostal muscles. They receive efferent lymphatic vessels running around the intercostal space and emerging from between the muscles or from their deep surface.

There may be one or two nodes in every intercostal space, and they link up to each other by a lymphatic channel that runs inferiorly to superiorly. The posterior intercostal chain may drain:

• for superior intercostal spaces to:
  • on the left, the thoracic duct:
    • directly, above the arch of the aorta
    • indirectly, via posterior mediastinal lymph nodes
  • on the right, the right lymphatic duct

in the lower intercostal spaces, to a descending intercostal trunk that eventually joins to the cisterna chyli below the diaphragm