Signs and symptoms

Local symptoms
Localized pain and swelling are the hallmark clinical features of bone sarcomas. The pain, which initially is insidious and transient, becomes progressively more severe and unremitting. Localized soft-tissue swelling, with or without associated warmth and erythema, may be present. A joint effusion may be observed, and range of motion of the adjacent joint may be limited and painful. Movement or weight-bearing of the involved extremity may exacerbate local symptoms.

Patients with tumors arising in the lower extremities can present with a painful limp. The neurovascular examination of the affected extremity is usually normal. Regional lymph nodes are rarely involved.

Pathologic fracture may also be a presenting sign, although a history of pain prior to fracture usually can be elicited.

Constitutional symptoms
These are rare in patients with bone sarcoma, but such symptoms as fever, malaise, and weight loss can be observed in those with Ewing's sarcoma.

Screening and diagnosis

Currently, there is no screening test for primary bone sarcomas. The diagnosis must be made by clinical and radiographic evaluations and confirmed by histopathologic analysis of biopsy-obtained tissue.

Physical examination
Physical examination should include an assessment of the local extent of the soft-tissue mass, if present, and its relationship to the adjacent joint.

Laboratory studies
A CBC may demonstrate anemia and/or leukocytosis associated with Ewing's sarcoma, but, in general, results of these studies fall within the normal range. Alkaline phosphatase and lactic dehydrogenase (LDH) levels may be elevated in patients with osteosarcoma or Ewing's sarcoma. An abnormal glucose tolerance test may be observed in patients with chondro-
sarcomas.

X-rays
Biplanar (anteroposterior and lateral) plain radiographs of the affected extremity provide critical information on the nature of the bone lesion. The specific site of involvement within the bone, the pattern and extent of bone destruction, type of periosteal changes, and the presence of matrix mineralization within the tumor, and of soft-tissue extension may be gleaned from plain films.

CT
Standard CT scans provide further delineation of many of these changes.

MRI
MRI is the imaging study of choice for evaluating the extent of an associated soft-tissue mass and the relationship of the tumor to the neurovascular structures, surrounding soft tissues, and the adjacent joint. The intramedullary extent of the tumor and presence of skip metastases within the bone are best demonstrated by MRI.

Bone scan
A bone scan is performed to screen for distant osseous metastases.

Chest radiographic studies
A plain film of the chest is required in any patient suspected of having a bone sarcoma. Once the diagnosis of malignancy has been established, a CT scan of the chest is a critical part of initial staging.

Biopsy
With few exceptions, a biopsy must be obtained to confirm the diagnosis. Tissue may be obtained by percutaneous (closed) or surgical (open) techniques. The biopsy should be performed by personnel expert in percutaneous biopsy techniques who are familiar with bone tumors and their treatment.

Biopsies performed at referring institutions have been reported to be associated with a higher incidence of misdiagnosis and complications, which may affect patient outcome. Optimally, the biopsy should be performed at the institution where definitive treatment will be given.