Hard lump under left nipple

Hi. My son recently found a hard lump directly under his left nipple. He is 13. The lump is very small, only 1 cm x 1cm and it is not painful. Also, his left and right nipples seem to be inverted a lot. They are not always inverted, and this happens moreso on the left. Should he go to the doctor for this? Thanks.

[CCF-RN,MSN-rf]

Dear superwizard188:  A lump in a 13 year old boy is unlikely to be breast cancer.  However, the general rule of thumb is that any lump should be evaluated by a physician.

[cfoxon]

A related discussion, hard and painful left nipple was started.