CT scans are useful in distinguishing between lipomas and liposarcomas. Fine-needle aspiration is indicated when the diagnosis of liposarcoma is suspected. Lipomas histologically resemble normal fat. When completely excised, a thin fibrous capsule surrounding the aggregate of adipocytes may be seen. Without a clinical or gross description, it often is impossible to distinguish between tumor cells and mature adipocytes.
Lipomas differ biochemically from normal mature fat.
Lipomas have increased levels of lipoprotein lipase. Multiple surgical techniques can treat lipomas. Carefully evaluate infiltrating lipomas when considering excision, since they can develop in intramuscular or intermuscular locations. They also can infiltrate into tendon, bone, and nerve, thus requiring careful microdissection to preserve important structures. Incise skin down to the lipoma capsule, and dissect to free the mass from the surrounding tissue.