Information
Editors
Bone Tumours
Essentials
- In the initial phase, the diagnosis of a primary bone tumour is based on clinical suspicion and x-ray findings. The abnormalities may sometimes be difficult to detect from routine x-rays.
- Magnetic resonance imaging is used as a second-line investigation.
- If a diagnosis is not reached with radiological investigations, a core biopsy specimen is obtained under CT guidance. The procedure is performed at the unit that will carry out any subsequent treatment.
- In bone tumour surgery done in limbs, the aim is limb-sparing surgery by using large tumour prostheses or banked bone for replacing the removed part. Amputations are only seldom necessary even in malignant tumours.
Malignant bone tumours
- Osteosarcoma is the most common primary malignant bone tumour especially in children, adolescents and young adults.
- The knee area and the upper part of the upper arm are the sites of predilection.
- X-ray findings are usually typical (picture 1).
- Prognosis is improved by early diagnosis.
- The treatment is carried out at specialized centres.
- Chondrosarcoma is a tumour originating from cartilaginous tissue and is encountered in patients of a more advanced age. Its emergence may also be associated with the hereditary condition known as MHO (Multiple Hereditary Osteochondromatosis) or Ollier disease.
Benign bone tumours
- Osteochondroma (picture 2) and enchondroma which occurs often in the bones of the hand (picture 3) are the most common benign bone tumours.
- Surgical treatment of an osteochondroma is often indicated due to the mechanical inconvenience and to the fracture risk associated with a finger enchondroma.
- Enchondromas in long bones like the humerus or femur need to be evaluated by a specialist group if their diameter exceeds 3 cm.
- Non-ossifying fibroma (NOF) is a typical incidental finding which does not require follow-up or procedures.
- An osteoid osteoma is treated with thermocoagulation (picture 4). In addtion to surgical treatment of an aneurysmal bone cyst, an etoxysclerol injection is used.
- A giant cell tumour is treated locally with curettage and cement filling (picture 5). If surgery is not possible, denosumab may be used.
- The most common cancers metastasising to the bone are (oestrogen-receptor positive) breast cancer, lung cancer (particularly small cell lung cancer), prostatic cancer and renal cancer.
- Bisphosphonates are currently used routinely to alleviate pain and reduce bone loss.
- Pathologic fractures of limb bone metastases are treated surgically. The patient's life expectancy significantly affects the surgical method.
- Prophylactic intramedullary nailing can be used if there is a risk of fracture. Local radiotherapy is usually given after the procedure.
Signs of good prognosis
- A highly specialised, slowly growing tumour
- A long metastases-free period after primary treatment
- Sclerotic metastases from the onset
- Lytic metastases that become sclerotic during treatment
- A solitary bone metastasis especially in a kidney cancer patient
- Small total tumour load
- No metastases in vital organs
- Absence of hypercalcaemia
- Absence of leucoerythroblastic anaemia
Sclerotic metastases
- Irradiation is effective in 80-90% of patients.
- The risk of pathological fractures is lower.
Lytic metastases
- There is a high risk of pathological fractures, especially in metastases in the upper part of the femur and diaphysis. First-line treatment often consists of radiotherapy.
- Lytic metastases in the spine may cause spinal cord compression through a tumour or a vertebral body compression fracture. The symptoms include weakness in the lower limbs, radicular paralysis symptoms or cauda equina syndrome.
- Metastases in the cervical spine are an indication for a cervical collar before treatment is started. Immediate surgery or radiotherapy is indicated if the patient develops symptoms of paralysis.
Assessment of treatment outcome
References
- WHO Classification of Tumours Editorial Board. Soft tissue and bone tumours. WHO classification of tumours, 5th edition, 2020.
- ESMO/European Sarcoma Network Working Group. Bone sarcomas: ESMO Clinical Practice Guidelines for diagnosis, treatment and follow-up. Ann Oncol 2014;25 Suppl 3():iii113-23. [PubMed]