There are four deep lymphatic channels for drainage of the breast:
- superior trunk:
- originates from subareolar plexus around nipple
 - drains from
- superficial and deep tissue around nipple, areola and periareolar region
 - parenchymal tissues of outer half of the breast
 
 - pierces fascia at the lateral border of pectoralis major to run to axillary nodes
 
 
inferior trunk:
þþ originate in subareolar plexus
- receives lymphatics from the medial half of the breast
 - takes same route as superior trunk to axilla
 - transpectoral lymphatics:
- arise from deepest surface of breast
 - pass through pectoralis major
 - pass along route of pectoral branch of thoraco-acromial artery
 - distribute lymph to apical axillary nodes
 
 - retropectoral lymphatics:
- originate in the superomedial parts of the deep breast
 - pass laterally deep to pectoralis major
 - supply the apical group of nodes
 
 
These must be contrasted with the cutaneous lymphatics.