Spindle Cell Sarcoma, Leg

43-year-old male with a history of swelling in the pre-tibial soft tissues of the left leg. The images demonstrate a well circumscribed T1 hypointense STIR hyperintense lesion within the pre-tibial soft tissues. The lesion is partially circumscribed. There is moderate surrounding soft tissue edema and stranding. The lesion solidly enhances. A spindle cell sarcoma was identified after excision. Spindle cell sarcoma arise from mesenchymal cell origin. They are a group of aggressive malignant soft tissue tumors which may result from malignant transformation of benign entities. Others present with delayed detection before their invasive nature is apparent. The most common clinical feature is swelling and a palpable soft tissue lesion. Treatment is with excision followed by radiotherapy.