Hello there I have read through your question and understand your concern. The most common cause of visible veins on breast is idiopathic thrombophlebitis which is a self limiting disease and does not require any treatment. At your age breast cancer is very rare but since you have described a swollen lymph node it is advisable to get a physical examination done by a surgeon. He may advise a mammogram or an MRI depending on the result s of physical examination. I hope that answers your question. If you have any further questions please feel free to write. Thank you for choosing healthcare magic.