My 18 year old son has a pea size lump in his suprasternal notch and he says it has a little pain. he has had it and it has gotten bigger.

Get it checked: its hard to determine what it could be without examining him and getting a little more history. depending on whether the lump is subcutaneous or deeper it could be anything from a cyst to a thyroid nodule. have him see a doctor.

Needs Evaluation: This site is a classic location of a possible thyroglossal cyst. There are many other causes, including lymph nodes. This will definitely need an evaluation by your doctor and follow recommendation/ ultrasound etc. It can get infected at times too. Once again have it seen by your doctor.