It sounds like your daughter is simply in the early beginnings of puberty. What you have described does sound very much like a breast bud, which is common particularly in girls at this stage. Oftentimes a small firm mass is appreciated right under the areolar (darker-colored) tissue on the chest. It can be on only one side and is movable, not attached to the muscle or ribs beneath, and does not cause any pain. There is no discharge from the nipple, no dimpling of the skin in the area, and no evidence of infection. Once someone feels it, however, the family tends to follow it more closely, checking it frequently to see if it changes at all. This can cause it to become sore because of the constant manipulation.
I do not think you need a second opinion at this time. A breast bud generally does not suggest that there are any significant hormonal problems or that this is related to breast cancer (if there is a family history of breast cancer, I would mention it to your child s doctor). By having her examined, the doctor gets a good history, checks to see if there are any other signs of puberty, any evidence of secondary sexual characteristics developing, or other possible causes for the lump.
Reassurance is appropriate along with just observation over time. If the area seems to be infected, seems to be getting larger, or discharge is noted from that nipple, then I would have her reevaluated.
What Can Be Done About Breast Pain?
Since breast pain is not an unusual part of breast development during the first signs of puberty, treatment for it should be simple, including over-the-counter pain medications such as ibuprofen and a warm compress for comfort. A supportive bra may also be helpful, no matter the breast size.
Important health information to be aware of is that adolescent boys will sometimes experience breast pain at the start of puberty.
What Other Things Can Cause Breast Pain in Adolescents?
Some of the first signs of puberty in your daughter are the development of pubic hair, the darkening of the areola, and of course, the onset of her menstrual cycle. In addition, her hormone levels will change, and where once she was able to wear a t-shirt under her athletic uniform, she may now require a sports bra for her changing body and breast development.
Along with cramps, headaches, and back pain, menstruation can cause breast tissue to become tender and sore. Many young women experience breast tenderness during their menstrual periods, especially if breast development is ongoing. If she experiences severe pain in her breasts during her menstrual period, consult with a pediatric health care provider, or if she's in her late teens, a pediatrician who specializes in gynecology or an OB/GYN for medical advice. Some cysts may develop in the breast tissue, causing pain and discomfort, though it's more likely that the natural development of a young woman's breasts is the cause of the pain.