MDM2 and lipoma: Immunohistochemical analysis revealed that the tumor was CK(−), MDM2(−), CDK-4(−), S-100(+), CD34(+), HNB45(−), Mela-A(−), 1% ki67(1%+), focal Desmin(+), and focal SMA(−), indicating a differentiated mature lipoma with mild fibrosis (Figure 4).