Lymphatics from most of the breast drains into axillary lymph nodes. The medial most poion of the breast drain through the chest wall into the internal mammary lymph nodes. So carcinoma in this patient which is in the upper outer quadrant spreads to the anterior, central and lateral group of axillary nodes. Aerial supply of breast is derived from branches of internal thoracic aery, lateral thoracic aery, and posterior intercostal aery. Venous drainage is primarily into the axillary vein but also into internal thoracic vein, subclan and azygos vein.