Sonographic appearances of superficial soft tissue lipomas

High-resolution real-time sonography was used to evaluate 35 superficial soft tissue lipomas. Thirty were located in subcutaneous tissues and 5 in superficial muscles. The lipomas were assessed for location, shape and size, boundaries, echotexture, homogeneity, and sound through transmission. All were elongated, with their greatest diameter parallel to the skin. Twenty-three lipomas (66%) showed a homogenous echotexture. Twenty-one (60%) were well defined, and the remainder showed ill-defined margins blending into the surrounding tissues. Twenty-nine percent of the lipomas were hypoechoic, 22% were isoechoic, 29% were hyperechoic, and 20% showed a mixed pattern. An elongated isoechoic or echogenic mass in the subcutaneous tissues should suggest the diagnosis of lipoma.