Lipomas are the most common soft-tissue tumor. These slow-growing, benign fatty tumors form soft, lobulated masses enclosed by a thin, fibrous capsule. Lipomas are common benign mesenchymal tumors. They may develop in virtually all organs throughout the body. The anatomy depends on the tumor site. Subcutaneous lipomas are usually not fixed to the underlying fascia. The fibrous capsule must be removed to prevent recurrence. The cause of lipomas is not completely understood, but the tendency to develop them is inherited. A minor injury may trigger the growth. Being overweight does not cause lipomas.