When cells divide abnormally and uncontrollably, they can form a mass or lump of tissue. This lump is called a tumor. Bone tumors form in your bones. As the tumor grows, abnormal tissue can displace healthy tissue. Tumors can either be benign or malignant.
Benign tumors aren’t cancerous. While benign bone tumors typically stay in place and are unlikely to be fatal, they’re still abnormal cells and may require treatment. Benign tumors can grow and could compress your healthy bone tissue and cause future issues.
Malignant tumors are cancerous. Malignant bone tumors can cause cancer to spread throughout the body.
Types of benign bone tumors
Benign tumors are more common than malignant ones. According to the American Academy of Orthopaedic Surgeons (AAOS), the most common type of benign bone tumor is an osteochondroma. This type accounts for between 35 and 40 percent of all benign bone tumors. Osteochondromas develops in adolescents and teenagers.
These tumors form near the actively growing ends of long bones, such as arm or leg bones. Specifically, these tumors tend to affect the lower end of the thighbone (femur), the upper end of the lower leg bone (tibia), and the upper end of the upper arm bone (humerus).
These tumors are made of bone and cartilage. Osteochondromas have been considered to be an abnormality of growth. A child may develop a single osteochondroma or many of them.
Nonossifying fibroma unicameral
Nonossifying fibroma unicameral is a simple solitary bone cyst. It’s the only true cyst of bone. It’s usually found in the leg and occurs most often in children and adolescents.
Giant cell tumors
Giant cell tumors grow aggressively. They occur in adults. They’re found in the rounded end of the bone and not in the growth plate. These are very rare tumors.
An enchondroma is a cartilage cyst that grows inside the bone marrow. When they occur, they begin in childhood and persist as adults. They tend to be part of syndromes called Ollier’s and Mafucci’s syndrome. Enchondromas occur in the hands and feet as well as the long bones of the arm and thigh.
Fibrous dysplasia is a gene mutation that makes bones fibrous and vulnerable to fracture.
Aneurysmal bone cyst
An aneurysmal bone cyst is an abnormality of blood vessels that begins in the bone marrow. It can grow rapidly and can be particularly destructive because it affects growth plates.