MANAGEMENT OF BENIGN BONE TUMORS

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1 MANAGEMENT OF BENIGN BONE TUMORS HISTORY AND EXAMINATION An adequate history and physical examination are the first and most important steps in evaluating a patient with a musculoskeletal tumor PRESENTING COMPLAINTS Patient may present with Incidental findings on x-rays Pain Mass Deformity Pathological Fractures Neurological symptoms PAIN CAUSES: rapid expansion with stretching of surrounding tissues,central hemorrhage degeneration in the tumor, an incipient pathological fracture. Benign bone tumors - activity-related pain if the lesion is large enough to weaken the bone If encapsulated in dense bone e.g. an osteoid osteoma is very painful

2 Soft-tissue tumors rarely complain of pain, but more often complain of a mass. Exceptions to this rule are nerve sheath tumors. Low back pain or pain in pelvis and hip is often first sign of existence of secondary deposits. SWELLING ONSET AND PROGRESS : insidious in cases of bone tumors, history of trauma drawn the attention of the patient towards the swelling. DURATION: malignant tumors grow rapidly with relatively short history then benign tumors few exceptions like CHONDROSARCOMA. SIMILAR SWELLINGS: Histiocytosis, Enchondroma, Osteochondroma, Fibrous dysplasia, Multiple myeloma, Metastases etc FAMILY HISTORY: multiple hereditary exostosis and neurofibromatosis. DEFORMITY Painful scoliosis Growth disturbance Flexion contractures Neurologic symptoms with spine involvement Limited joint motion FRACTURE PATHOLOGICAL FRACTURE may be the first and only clinical signal Usually trival injury and fracture at the cortico-cancellous junctions Break in the midshaft of long bones with trival injury should be regarded as pathological until proved otherwise.

3 upper femur patho fracture (with the so-called shepherd s crook deformity) LOCAL EXAMINATION Evaluation of the patient's general health INSPECTION: (a) Swelling: all swellings arising from bone will be fixed to it (b)overlying skin: e.g, tense, glossy with dilated veins in osteosarcoma (c)pressure effects: oedema,paresis (f)muscular wasting: if neurovascular status is compromised or disuse atrophy. (g) Neighboring joints: e.g Deformity, Contractures (g) Shortening or Lenghtening of bone: either provokes the growth or destroy epiphyseal cartilage. PALPATION Location Shape : e.g. pedunculated generally exostosis. Consistency: e.g. bony hard in osteoma, sometimes Egg shell crackling in GCT, Osteosarcoma variable. Mobility Tenderness local temperature change with position should be noted Atrophy of the surrounding musculature neurological deficits and adequacy of circulation Potential sites of lymph node metastases

4 NON-TUMOUROUS CONDITIONS THAT MAY MIMIC TUMOURS Osteomyelitis (esp Brodie's abscess) Eosinophilic granuloma Subchondral degenerative cyst Intraosseous ganglions Metabolic Disease Paget's Osteitis fibrosa cystica & Brown tumour Post-trauma Stress fracture Myositis ossificans

5 LABS In general lab investigations are normal in benign bone tumours Labs are done to exclude from other conditions and malignancies CBC: mostly to exclude other conditions e,g leukocytosis in osteomyelitis ESR :elevated in infection; metastatic carcinoma, Ewing sarcoma, lymphoma, leukemia, and histiocytosis Serum calcium: hyperparathyroidism, metastasis, multiple myeloma, sarcoidosis. Alkaline phosphatase: elevated in metabolic bone disease, metastatic disease, osteosarcoma, Ewing sarcoma, or lymphoma Serum protein electrophoresis : gama-globulin raised in multiple myeloma PSA: suggest prostatic carcinoma. Bun & creatinine: elevated with renal tumors, and a urinalysis may reveal hematuria in this setting URINALYSIS: Bence jones protein QUESTIONS TO ASK WHEN STUDYING AN X-RAY Is the lesion solitary or are there multiple lesions? What type of bone is involved? Where is the lesion in the bone? Are the margins of the lesion well- or ill-defined? Are there flecks of calcification in the lesion? Is the cortex eroded or destroyed? Is there any periosteal new-bone formation? Does the tumor extend into the soft tissues?

6 BONE SCAN A bone scan can often find a problem days to months earlier than a regular x- ray test An effective method for screening the whole body for bone metastases 99m tc methylene diphosphonate (MDP), is the most frequently used isotope Help in detecting metastatic bone deposits by the increased osteoblastic activity they induce; this finding is considered to be an indirect marker of tumor. BONE SCAN Indications Staging in asymptomatic patients Evaluating persistent pain in the presence of equivocal or negative radiographic findings Determining the extent of bone metastases in patients with positive radiograph findings Differentiating metastatic from traumatic fractures by assessing the pattern of involvement Determining the therapeutic response to metastases. Main role is demonstration of multiple lesions

7 COMPUTED TOMOGRAPHY Best for assessing mineralization & bony details Valuable in the evaluation of focal abnormalities seen on bone scinti-scans that cannot be confirmed by using radiographs Further assessment of radiographically negative areas in patients who are symptomatic and in whom metastases are suggested clinically. Osteolytic, sclerotic, and mixed lesions are depicted well on CT scans CT is useful in guiding needle biopsy of lesions in bones with complex shapes such as the vertebrae and the ilia COMPUTED TOMOGRAPHY Benign bone tumors Violation of cortex Matrix mineralization Shows local extent of tumor Intraosseous Extension into soft tissue Shows areas that plain XR visualize poorly Spine Pelvis Reliable method of detecting pulmonary mates. MRI Best for assessing soft tissue Determines extent of disease Very sensitive for Soft tissue tumors Soft tissue extension Marrow involvement Joint & epiphyseal involvement Reactive zone & satellite lesions MRI is excellent to determine extent of disease (reactive zone) but often very poor in diagnosing type of tumor Eg. Myositis ossificans appears benign on plain XR but appears very aggressive with significant surrounding reactive change (edema) on MRI Shows relationship to neurovascular bundle well BIOPSY AIMS: To determine whether benign or malignant To determine cell line To grade lesion

8 A biopsy can be done by fine needle aspiration, core needle biopsy, or an open incisional procedure. Done only after clinical, laboratory, and radiographic examinations are complete. If evaluation suggest a primary malignancy in D D pt should be referred to a musculoskeletal oncologist before biopsy. STAGING OF BENIGN BONE TUMORS Latent Well-defined margin. Grows slowly and then stops Remains static/heals spontaneously E.g. Osteoid osteoma Active Progressive growth limited by natural barriers Not self-limiting. Tendency to recur E.g. Aneurysmal bone cyst Aggressive Growth not limited by natural barriers (e.g. giant cell tumor) STAGE 1 Lesions are intra-capsular, usually asymptomatic, and frequently incidental findings. Radiographic features include a well-defined margin with a thick rim of reactive bone. There is no cortical destruction or expansion. TREATMENT: These lesions usually do not require treatment because they do not compromise the strength of the bone and usually resolve spontaneously STAGE 2 Lesions also are intra-capsular, but are actively growing and can cause symptoms or lead to pathological fracture. They have well-defined margins on radiographs but may expand and thin the cortex. Usually they have only a thin rim of reactive bone. Treatment usually consists of extended curettage STAGE 3 Lesions are extracapsular. Their aggressive nature is apparent clinically and radiographically. They usually have broken through the reactive bone and possibly the cortex. MRI may show a soft-tissue mass, and metastases may be present in 5% of patients with these lesions. Treatment consists of extended curettage and marginal or even wide resection, and local recurrences are common.