Lipoma is a common benign skin tumor arising from the subcutaneous adipose (fatty) tissue. It is usually mobile (i.e. it’s loose and you can roll it around under the skin). It usually is small and does not attract attention to itself unless it becomes large and causes pain, or is located near a nerve and causes pain. If a lipoma is large, rapidly growing in size, deeply seated, immobile or irregularly shaped, its likelihood of being a liposarcoma (cancer) is much greater, and it should be examined by a physician.
Two common reasons requiring excision are to relieve pain and to establish diagnosis (benign vs. malignant).
Read more from free sources at Mayo Clinic and Cleveland Clinic.
Case Study: Lipoma removal: A Total of Two Weeks from Phone Call to Discharge