Liposarcoma is a very rare malignant tumor affecting the head and neck area. Since it is an invasive and life-threatening disease, active treatments is necessary. However, differential it from lipoma, its corresponding benign counterpart, may be difficult. Herein, we report a rare case of posterior neck myxoid liposarcoma in a 72-year-old man who was initially misdiagnosed with lipoma, including a literature review of differential diagnosis between lipoma and liposarcoma.