Hi,
The doctor must be sure about the lesion being benign and thats why has advised you a follow up examination in 6 months to see for any changes in size or shape etc.
You could talk to your doctor about removal of the cyst or aspiration of the cyst fluid - this is done under ultrasound guidance usually and then sent for lab analysis.
This would help in clearing your doubts and also reaching a confirmed diagnosis.
You should carry out regular breast self examinations and report any abnormal features to your doctor.
Keep us posted and let us know if you have any doubts.
Regards.
Well cysts don't turn into breast cancer but I would follow up as recommended by the Dr. Sometimes they can absolve or they can be aspirated or even removed if necessary.