in·ter·nal tho·rac·ic lym·phat·ic plex·us
a lymphatic plexus, including the parasternal lymph nodes, with their vessels, situated along the course of the internal thoracic veins.
plexus mammariusAn obsolete term for:
(1) A nerve plexus in the breast parenchyma;
(2) A network of autonomic nerves surrounding the internal thoracic artery.