A lesion is a localized pathological change in a tissue. Many diseases affect the functioning or structure of bones, which are responsible for support, movement and synthesis of blood cells in the marrow. Bone lesions may be classified in various ways, including cancerous growths, non-cancerous tumors and and other lesions.
Cancerous Masses
The most common cancerous lesions found in bones are metastatic cancer, that is they come from a cancer that grew in another part of the body and migrated to the bone. According the Merck Manual, the most common types of cancer to metastasize to bone are breast, lung, prostate, kidney, colon and thyroid. Multiple myeloma is the most common primary cancerous bone tumor, but it is often considered a marrow cell tumor. Osteosarcoma is the second most common, and occurs most often in young adults and children. In contrast, chondrosarcoma occurs more in the elderly and grows as cartilage at the ends of bones. Ewing's sarcoma occurs in 10-to-25-year-olds.
Benign Masses
According to the American Academy of Orthopaedic Surgeons, some of the the most common benign tumors in the bone are osteochondroma, enchondroma and benign giant cell tumor. Osteochondroma is the most common, occurs in people aged 10 to 20, and may cause single or multiple lesions. Enchondromas occur in slightly older patients with a median age around 30, and may be asymptomatic, found incidentally on x-ray. Benign giant cell tumors affect people in their 20s and 30s. They destroy bone as they grow and tend to recur after treatment.
Other Lesions of Bone
Some other lesions of bone include fibrous dysplasia and bone cysts. Fibrous dysplasia is abnormal bone development during childhood caused by a genetic mutation which causes cells to form abnormal fibrous bone. The abnormal bone expands, weakening that area of bone, causing pain, fractures and deformity. Bone cysts are hollowed-out cavities in the bone that predispose the bone to fractures.
References
- Mayo Clinic: Bone Cancer: Causes
- Merck Manuals: Tumors of Bones and Joints
- National Cancer Institute: Bone Cancer: Questions and Answers
- American Academy of Orthopaedic Surgeons: Your Orthopaedic Connection: Bone Tumor
- American Academy of Orthopaedic Surgeons: Your Orthopaedic Connection: Fibrous Dysplasia
