Joshua,

The FNAC being positive means that there have been abnormal cells in the cyst as shown by the fine needle aspiration cytology. (FNAC) It is possible that the reason why the blood tests have shown negative is that the body isn't building any antibodies to the cyst and it has not had time to spread. Your friend should consult their doctor and work through a plan of action based on his recommendation and the tests. There is a little more information about the test here in the breast pain section.

I hope this helps. Remember, Health Central is a great resource for getting the information you need to manage your health care, but can not take the place of your doctor's solid medical advice.

Take care and stay in touch!

Vicki M