Myxoinflammatory fibroblastic sarcoma(MIFS) is a rare low-grade, malignant soft tissue tumor that is usually observed in the extremities of adult patients. Magnetic resonance imaging findings for this tumor type have rarely been reported. We report a case involving the distal left femur of a middle-aged man and tumoral invasion of the bone, which, to our knowledge, has been previously described only once. He was treated with distal femoral tumor resection and reconstruction with a modular prosthesis. Histopathologic diagnosis confirmed MIFS. We reviewed literature of the diagnostic imaging and bone invasion findings associated with this tumor type. Myxoinflammatory fibroblastic sarcoma (MIFS) is a rare low-grade, malignant soft tissue tumor that is usually seen in the extremities of adult patients. We report a case involving the distal left femur of a middle-aged man and tumoral invasion of the bone, which, to our knowledge, has been previously described only once. He was treated with distal femoral tumor resection and reconstruction with a modular prosthesis. Histopathologic diagnosis confirmed MIFS. We reviewed literature of the diagnostic imaging and bone invasion findings associated with this tumor type.