Myofibroblastoma is a benign tumor caused by the abnormal proliferation of fibrous tissue in the muscles, which is not common in clinical practice. It usually occurs in the extremities, especially in the lower extremities and upper arms, and in some patients it can occur in the rectus abdominis muscle and can appear as an elevated mass deep under the skin reaching the muscle layer, mostly oval in shape, which can push some patients to have pressure pain. Although benign tumors, they are invasive and need to be expanded during surgery.