Malignant Tumors: Soft Tissue and Bone

Malignant Bone Tumors

Malignant bone tumors are a group of lesions that vary in their tissue makeup and behavior and range from locally aggressive tumors that usually do not metastasize to high grade sarcomas with a poor prognosis. They affect all age groups and all bony sites. Diagnosis of the specific type of malignant bone tumor is critical since the treatment for each type varies. Treatment is extremely aggressive in nature usually involving one or more of the following: chemotherapy, radiation therapy, surgery (resection) and bone marrow (stem cell) transplants.

• Osteosarcoma
• Chondrosarcoma
• Malignant Fibrous Tumors of Bone (MFT)
• Adamantinoma
• Chordoma
• Ewing's Sarcoma
• Malignant Lymphomas of Bone
• Multiple Myeloma
• Metastatic Bone Tumors of the Skeleton

Malignant Soft Tissue Tumors

Malignant soft tissue tumors, or soft tissue sarcomas, are more common than bone sarcomas. They usually occur in adults and present as a large painless or painful soft tissue mass. Because benign soft tissue "lumps" are far more common than malignant ones, the diagnosis of a soft tissue sarcoma may be made after excision of a presumed benign mass at a local hospital or in the local doctor's office. When the pathologist reports a sarcoma, the patients are referred to us, a cancer center, for staging studies to assess the local extent and/or spread of the tumor and for further treatment (surgery, chemotherapy or radiation).

Soft tissue tumors are also classified by their tissue type and grade. The higher the grade, the greater the chance for aggressive growth at the original site and for metastases to distant sites. The most common metastatic site is the lungs. Certain sarcomas, such as synovial sarcoma, epithelioid sarcoma and rhabdomyosarcoma (the most common childhood soft tissue sarcoma) may also spread to the lymph nodes.

Staging a soft tissue tumor involves evaluating the histology (tissue grade) of the tumor, how extensive the tumor is at the primary site, and whether or not there are distant metastases. All of these characteristics help describe the tumor's behavior (biologic activity), the patient's prognosis and the best treatment option.

The MRI scan is the best imaging study for soft tissue tumors because of its sensitive technique to show differences between normal and sarcoma tissue. It also clearly shows the relation of the tumor to nearby nerves and blood vessels. A chest CT scan is always necessary to rule out lung metastases, and a biopsy will determine diagnosis and treatment.

Types of Malignant Soft Tissue Tumors:

• Liposarcoma
• Undifferentiated Pleomorphic Sarcoma (UPS)
• Synovial Sarcoma
• Leiomyosarcoma
• Rhabdomyosarcoma
• Angiosarcoma
• Malignant Peripheral Nerve Sheath Tumors (MPNST)