True about lymphatic spread of Ca breast

Lymphatic spread occurs through: Subareolar Sappey's lymphatic plexus (presently its Significance is discounted). Cutaneous lymphatics. Intramammary lymphatics. Lymphatic drainage of the breast is predominantly through axillary (75%) and internal mammary lymph nodes. Axillary group of nodes are: 1. Anterior along lateral thoracic vessels (Pectoral). 2. Central embedded in fat in the centre of the axilla. 3. Posterior along subscapular vessels. 4. Lateral along axillary vein. 5. Apical lies above pectoralis minor tendon in continuity with the lateral nodes and receive efferents from all the groups. Spread to these lymph nodes occur by lymphatic permeation. Interpectoral, lies between pectoralis major and minor muscle (Rotter's nodes). Presently involvement of these lymph nodes are considered due to retrograde spread. These lymph nodes are cleared during Patey's mastectomy. From axillary lymph nodes spread occurs to supra clavicular lymph nodes by lymphatic embolisation. Ref; (page no; 536 ) 5th edition of SRB&;S manual of Surgery