Molecular testing for MDM2 amplification should be considered in recurrent lipomas, lipomatous tumors with equivocal cytologic atypia, large lipomatous tumors (>15 cm) without cytologic atypia, and lipomatous tumors lacking cytologic atypia in the retroperitoneum, pelvis, and abdomen [42]. The gene discussed is MDM2; the disease is tumor of adipose tissue.