Non-Surgical Management of Benign Bone Tumors

Primary bone tumors are extremely rare accounting for 0.2 % of all tumors. Bone tumors develop when cells within a bone divide uncontrollably, forming a lump or mass of abnormal tissue.

Most bone tumors are not cancerous (benign). Benign bone tumors almost never metastasize and are best classified by the matrix which the tumor cells produce such as bone, cartilage, fibrous tissue, fat or blood vessel. Among the most common benign tumors involving bone are endochondroma, osteochondroma, nonossifying fibroma, chondroblastoma, osteoid osteoma, osteoblastoma, periosteal chondroma, giant cell tumor, and chondromyxoid fibroma. Some conditions such as aneurysmal bone cyst, unicameral bone cyst, and fibrous dysplasia are sometimes grouped with benign bone tumors.

In contrary to what most people expect, they occur most frequently between the ages of 5 to 25 years and in the areas of greatest bone growth, with about 60% of cases in the knee region. For this reason, they can cause osteoarticular deformities, fractures, limb length discrepancies, gait disturbances.

The diagnosis and treatment of bone tumor is complex and requires a multidisciplinary approach. Plain radiographs (x-ray), MRI and occasional CT are usually sufficient to make a radiological diagnosis.  Some benign bone tumors have a characteristic and typical radiographic appearance, while others are more challenging. The clinic- radiological diagnosis is confirmed by biopsy and histopathology.

The treatment of benign bone tumors depend upon the age of the patient, symptoms, the natural history, anatomical location and associated morbidity. Historically, most of the benign bone tumors requiring surgery were treated with either curettage or resection with reconstruction. Despite the fact that surgery is the standard treatment, it has its own complications like damage to growth plate, infection, fracture, and limb length discrepancy.

Recently, novel systemic therapies are available. Fibrous dysplasia can be treated with bisphosphonates, and GCT responds to denosumab. In fact, denosumab has been approved for the treatment of non resectable GCT.  Aneurysmal bone cyst has been treated with sclerosing agents by percutaneous injection, yielding good results. Radiofrequency thermal ablation (RFTA) is considered the treatment of choice for osteoid osteomas, in which it has long been safely used. Other benign conditions (chondroblastoma, osteoblastoma, giant cell tumour, etc.) can also be treated by this technique. These treatment options has shown new horizon for providing a less morbid and function preserving option for management of benign bone tumors. Further indications are now emerging, with reports of good outcomes in treating other primary bone tumors.