Hey, I'm a 15 yr old female with a hard, golf ball sized lump on the bone just above my knee to the side. it's been there for as long as i can remember, at least ten years with no symptoms or changes to it's size. it doesn't bother me at all when I move around or anything so I easily forget it's even there, but it is a strange lump so do you think it could be cancer? Please share
From your description and your age, this could be an osteochondroma. This is a benign tumor that occurs during childhood and is actually made up of normal bone with a cartilage cap.
In growing children, the physis (growth plate) is located at the ends of the long bones. As the physis moves along with the growing bone, a nest of cells can get left behind. Since these cells are programmed to produce bone, they make a small spike of bone, with the cartilage cap at the tip of it.
Osteochondromas are most commonly seen at the proximal tibia and distal femoral physes, or around the knee. But, they can occur anywhere there is a growth plate.
You should probably have the area x-rayed, as the diagnosis of osteochondroma can be made on plain x-ray.
They do not need to be treated unless they are causing problems. Some are large enough that they interfere with the smooth gliding of muscles and tendons with activity. If it is bothering the patient, once the he/she has reached skeletal maturity, the osteochondroma can be excised. But, again, if it is not bothering you, it does not need to be treated.
However, you should get a diagnosis. If it is an osteochondroma, you do need to know that that is what it is. On very, very rare occasions, the osteochondroma can undergo malignant transformation to a chondrosarcoma. This usually occurs later in life, and is manifested by increasing in size and/or the development of pain in the lesion.
So, you might want to have the knee and the area of the lesion x-rayed, just to get a diagnosis. But, it really sounds like an osteochondroma.