could simply indicate a breast cyst
, a follow up sonography will be mandatory and might even require a needle biopsy
to confirm the pathology of the cyst. The most common cyst/growth/tumor is a fibroadenoma
which is harmless and is also called a mouse tumor as it is extremely mobile. A simple surgical procedure can remove the growth without and real complications.
Do not worry. Your doctor will decide whether the growth requires surgery or not and the best surgical approach will be chosen to avoid scars.
Hope this helps.