A lipoma is a benign (non-cancerous) tumor made up of fat cells. They usually appear as soft, movable lumps under the skin and can vary in size. Lipomas are most commonly found on the arms, back, and thighs, but they can develop anywhere on the body. They are generally painless and do not require treatment unless they cause discomfort or cosmetic concerns. Although lipomas are harmless, it's important to have any new lumps checked by a healthcare professional. In rare cases, a lipoma may be mistaken for other conditions, such as liposarcoma, a type of cancer. Regular monitoring can help ensure that any changes are addressed promptly.