Sarcoma

Sarcoma is a group of cancers that arise from mesenchymal (connective) tissues such as bone, cartilage, fat, muscle, blood vessels, or other supporting tissues. Unlike carcinomas, which originate in epithelial cells, sarcomas can develop in nearly any part of the body and are generally considered rare compared with more common cancers.

Sarcomas are broadly classified into soft tissue sarcomas (STS) and bone sarcomas. STS include subtypes such as liposarcoma, leiomyosarcoma, synovial sarcoma, rhabdomyosarcoma, angiosarcoma, and undifferentiated pleomorphic sarcoma. Bone sarcomas include osteosarcoma, chondrosarcoma, and Ewing sarcoma. The choice of treatment and prognosis depends on the exact histology, location, and stage of the tumor.

Symptoms often begin as a painless or mildly tender lump or swelling. In bone sarcomas, pain, swelling, functional limitation, or a fracture may occur. Diagnosis typically involves imaging (MRI or CT, X-ray, sometimes PET), followed by a biopsy to confirm the histologic type. Staging uses the TNM system and considers tumor grade. Molecular testing can identify characteristic genetic changes in certain subtypes (for example, EWS-FLI1 in Ewing sarcoma).

Treatment is usually multidisciplinary. Surgery to remove the tumor is central when feasible, with limb-sparing approaches for many soft tissue sarcomas. Radiation therapy and chemotherapy are commonly used, particularly for high-grade tumors or specific histologies; some subtypes have targeted therapies or immunotherapy options in selected cases.

Risk factors include certain inherited syndromes such as Li-Fraumeni, hereditary retinoblastoma, and neurofibromatosis type 1, as well as prior radiation exposure. Prognosis varies by histology, grade, stage, and location, with localized disease offering better survival than metastatic disease. Sarcomas are rare overall, and management is individualized to the tumor’s characteristics.