Lipomas are considered benign lesions, but some lipomas may undergo malignant transformation into liposarcomas. If a lipoma becomes malignant, its appearance may change, such as an increase in size, indistinct borders, hardening of the lipoma, and it may even cause pain in the area of the lipoma, with the possibility of local thrombosis and other conditions. It is necessary to visit a hospital promptly for examination and treatment. When necessary, the lipoma should be completely excised and sent for pathological examination to facilitate further treatment. If it is confirmed to be malignant, a wider excision may be needed, and, if necessary, the surrounding lymph nodes may need to be cleared.