There are a variety of types of bone and soft tissue tumors, and each one has its own particular behavior, treatment and patient outcome.
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Bone & Soft Tissue Tumors and Benign vs. Malignant Tumors
Bone and soft tissue tumors are rare. There are a variety of types and each one has its own particular behavior, treatment and patient outcome. The cause (etiology) of tumors is basically unknown. Some researchers have suggested a genetic cause because of the increased incidence in patients with certain conditions (hereditary osteocartilaginous exostosis, Maffucci's syndrome, Paget's disease) and because certain tumors have genetic mutations of the tumor cells. Bones in an area that has had radiation therapy have shown an increase in rate of malignant transformation. Trauma also has been discussed as a cause. However, most often it is more likely that the traumatic event or injury brings attention to a tumor that has already been present (pre-existing) rather than causing it.
Bone and soft tissue tumors are classified by their cell or tissue type and their ability to spread beyond the original site (metastasize). Thus, bone and soft tissue tumors fall into two major categories. They are benign (unable to spread) or malignant (able to spread to other parts of the body, especially to the lungs or other bones). Benign tumors are not life threatening, malignant tumors may be. Benign tumors may heal or resolve on their own. They may be left alone and just 'watched' over the years, or may respond well to minor surgery if they are causing symptoms, likely to lead to fracture, or injuring underlying bone and surrounding soft tissue, blood vessels and nerves.
Malignant tumors, bone and soft tissue, also known as sarcomas are a realtively rare form of cancer, often require treatment with drugs (chemotherapy) and/or radiation therapy and major surgery. Chemotherapy is used for its systemic effect, that is, once given it circulates throughout the body to stop malignant cells from spreading to other areas of the body. Radiation is used for its local effect, that is, the beam of radiation penetrates the area of the tumor and surrounding tissue to kill tumor cells causing necrosis (cell death) and sometimes reduction in the tumor size.
Years ago, surgery meant amputation. Now surgery involves wide resection (complete removal of the tumor and a little normal and reactive surrounding tissue) with options to spare the limb (referred to as limb-sparing procedures). These options involve replacing the tumor bone with a donor bone (allograft) and securing it in place with a metal plate and screws, or replacing the tumor bone with a metal prosthesis (hardware similar to total joint replacements but more complex). An amputation may be necessary if the tumor invades surrounding blood vessels and nerves.
The type of surgical procedure to remove a tumor is categorized by the amount of surrounding tissue removed with the tumor. This border of surgical resection is called the tumor margin. There are basically four margins, thus four general ways to remove a tumor. A curettage or scraping of the lesion keeps the excision or resection (removal) of the the tumor within the walls or capsule of the tumor. A marginal excision is removal of the tumor along with a small amount of surrounding tissue called the reactive zone. A wide excision involves removal of the tumor, reactive zone and some normal tissue. A radical excision is removal of the tumor and the entire bone or muscle that contained the tumor referred to as compactment. All tumor specimens are sent to pathology to be examined for microscopic cells left behind in the margins. Results are reported as positive or negative margins. If margins are positive cells have been left behind and, additional excision may be necessary, or if the tumor is malignant, postoperative radiation therapy to the area may be advised.