Lipomas are non-cancerous fatty tissue tumors that develop underneath the skin. They typically appear as soft, movable nodules or bumps and can form anywhere on the body. In most cases, lipomas are harmless and develop slowly. However, removal may be needed if a lipoma becomes painful, irritating, or grows very large. An imaging test, like an MRI or CT scan, is sometimes used to confirm a diagnosis before removal takes place. Although the exact cause of lipomas is not fully understood, some individuals may be more prone to them than others.