
The lymphatic and venous drainages of the breast are of great importance in the spread of carcinoma.
About three quarters of the lymphatic drainage is to the axillary nodes: (1) Lymphatics pass around the edge of the pectoralis major and reach the pectoral group of axillary nodes;
(2) routes through or between the pectoral muscles may lead directly to the apical nodes of the axilla;
(3) lymphatics follow the blood vessels through the pectoralis major and enter the parasternal (internal thoracic) nodes;
(4) connections may lead across the median plane and hence to the contralateral breast;
(5) lymphatics may reach the sheath of the rectus abdominis and the subperitoneal and subhepatic plexuses.
It...