Signs and Symptoms of Osteosarcoma

Osteosarcomas are usually found because of the symptoms they are causing.

Pain and swelling

Pain in the affected bone (usually around the knee or in the upper arm) is the most common symptom of osteosarcoma. At first, the pain might not be constant and might be worse at night. The pain often increases with activity and might result in a limp if the tumor is in a leg bone.

Swelling in the area is another common symptom, although it might not occur until later. Depending on where the tumor is, it might be possible to feel a lump or mass.

Limb pain and swelling are very common in normal, active children and teens. They are much more likely to be caused by normal bumps and bruises, so they might not prompt a doctor visit right away. This can delay a diagnosis. If your child has these symptoms and they don't go away within a few weeks (or they get worse), see a doctor so that the cause can be found and treated, if needed.

These symptoms are less common in adults, so they should be a sign to see a doctor even sooner.

Bone fractures (breaks)

Although osteosarcoma might weaken the bone it develops in, fractures (breaks) are not common. Exceptions are rare telangiectatic osteosarcomas, which tend to weaken bones more than other forms of osteosarcoma and are more likely to cause breaks at the tumor site.

People with a fracture next to or through an osteosarcoma often describe a limb that was sore for a few months and suddenly became very painful when the fracture occurred.

The American Cancer Society medical and editorial content team
Our team is made up of doctors and master's-prepared nurses with deep knowledge of cancer care as well as journalists, editors, and translators with extensive experience in medical writing.

Anderson ME, Randall RL, Springfield DS, Gebhart MC. Chapter 92: Sarcomas of bone. In: Niederhuber JE, Armitage JO, Doroshow JH, Kastan MB, Tepper JE, eds. Abeloff’s Clinical Oncology. 5th ed. Philadelphia, Pa: Elsevier; 2014.

Gorlick R, Janeway K, Marina N. Chapter 34: Osteosarcoma. In: Pizzo PA, Poplack DG, eds. Principles and Practice of Pediatric Oncology. 7th ed. Philadelphia Pa: Lippincott Williams & Wilkins; 2016.

O’Donnell RJ, DuBois SG, Haas-Kogan DA. Chapter 91: Sarcomas of bone. In: DeVita VT, Lawrence TS, Rosenberg SA, eds. DeVita, Hellman, and Rosenberg’s Cancer: Principles & Practice of Oncology. 10th ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 2014.

Last Medical Review: December 15, 2017 Last Revised: January 30, 2018

American Cancer Society medical information is copyrighted material. For reprint requests, please see our Content Usage Policy.