Soft tissue sarcomas are a group of tumors that originate from mesenchymal cells, or cells that give rise to connective tissues and structural tissues. These tumors include fibrosarcomas, peripheral nerve sheath tumors, and hemangiopericytomas, leiomyosarcomas, and liposarcomas. These tumors tend to be locally invasive and send out small finger-like projections that extend into surrounding tissues. Risk of metastasis is dependent on tumor grade. Low grade tumors have a low risk (10%) while high-grade tumors have a moderate risk (40%). These tumors typically appear on the trunk, limbs or head and neck region, and tend to grow slowly. Diagnosis is made with a biopsy of the mass, as fine needle aspiration does not tend to yield diagnostic quality samples. However, aspiration can be used to rule out benign lipomas and other causes of skin growths. Further testing may include biopsy or aspiration of local lymph nodes, chest radiographs (x-rays), and CT scan of the mass to evaluate extent of invasion. CT scan is very helpful when planning for surgery, which is typically the first option for treatment. Wide margins of at least 3 cm around and 1-2 fascial planes deep to the tumor are taken to minimize the risk of tumor regrowth. Surgery may be repeated if regrowth occurs or when margins are incomplete. Other treatment options include radiation therapy following surgery for incompletely excised tumors. If metastasis is noted then chemotherapy or other systemic therapies may be recommended. Amputation may be used to control local disease when located on the limbs, but it does not affect metastasis or survival time. For grade I and II tumors treated with surgery followed by radiation therapy a median survival time (MST) of over 4 years is reported, while an MST of roughly 3 years is reported for grade III. Prognosis is much worse when metastasis is noted with a reported MST of 250 days. In general, prognosis determined by local disease control and not distant metastasis.