Bone<unk> s Diagnosis of bone<unk> s begins with a thorough history and physical examination which may reveal characteristic signs and symptoms (see Signs and Symptoms above). Laboratory studies are not particularly useful in diagnosis, although some bone<unk> s (such as osteosarcoma) may be associated with elevated alkaline phosphatase levels, while others (such as Ewing<unk>  can be associated with elevated erythrocyte sedimentation rate. Importantly, however, none of these laboratory findings are specific to bone<unk> s, meaning that elevations in these lab values are associated with many other conditions as well as<unk> , and thus cannot be relied upon to conclusively diagnose<unk> . Imaging studies are critically important in diagnosis, and most clinicians will order a plain radiograph (X-ray) initially. Other imaging studies commonly used in diagnosis include magnetic resonance imaging (MRI) studies and radioisotope bone scans. Computed tomography (CT) imaging typically is not used in diagnosis of most types of bone<unk> , although it is an important tool for staging (see below). Definitive diagnosis requires biopsy of the tumor and careful review of the biopsy specimen by an experienced pathologist. Soft tissue<unk> s Diagnosis of soft-tissue<unk> s also begins with a thorough history and physical examination. Imaging studies can include either CT or MRI, although CT tends to be preferred for soft tissue<unk> s located in the thorax, abdomen, or retroperitoneum. Positron emission tomography (PET) also may be useful in diagnosis, although its most common use is for staging (see below). As with bone<unk> s, definitive diagnosis requires biopsy of the tumor with evaluation of histology by a trained pathologist. Staging In general, cancer staging refers to how advanced a cancer is, and usually it is based upon factors such as tumor size and whether it has spread to other parts of the body. Staging is important because the stage affects the prognosis (likely outcome), as well as the types of treatments that are likely to be effective against the cancer. With<unk> s, staging requires a determination of whether the tumor has grown into surrounding tissues ("local invasion"), as well as imaging to determine whether it has spread (a process known as "metastasis") to lymph nodes (forming "nodal metastases") or to other tissues or organs in the body (forming "distant metastases"). The most common imaging tools used for staging bone<unk> s are MRI or CT to evaluate the primary tumor, contrast-enhanced CT of the chest to evaluate whether the cancer has spread (i.e., metastasized) to the lungs, and radioisotope bone scan to evaluate whether the cancer has spread to other bones. Staging for soft tissue<unk> s typically includes imaging of the primary tumor by MRI or CT to determine tumor size, as well as contrast-enhanced CT of the chest to evaluate for metastatic tumors in the lungs. Grade Like some other cancers,<unk> s are assigned a grade (low, intermediate, or high) based on the appearance of the tumor cells under a microscope. In general, grade refers to how aggressive the cancer is and how likely it is to spread to other parts of the body ("metastasize"). Low-grade<unk> s have a better prognosis than higher-grade<unk> s, and are usually treated surgically, although sometimes radiation therapy or chemotherapy are used. Intermediate- and high-grade<unk> s are more frequently treated with a combination of surgery, chemotherapy, or radiation therapy. Since high-grade tumors are more likely to undergo metastasis (invasion and spread to locoregional and distant sites), they are treated more aggressively. The recognition that many<unk> s are sensitive to chemotherapy has dramatically improved the survival of patients. For example, in the era before chemotherapy, long-term survival for pediatric patients with localized osteosarcoma was only about 20%, but now has risen to 60–70%.
Sarcoma
Angiosarcoma
Soft-tissue sarcoma
Hemangiosarcoma
Xanthoma
Myosarcoma
Epithelioma
Liposarcoma