Lipoma
Benign tumor of fat cells
Most common soft tissue tumor of adults
Common in mid-adulthood
Arise in the extremities, trunk
Can also rarely arise in muscle tissue
Soft, well-defined, mobile masses
Painless
Encapsulated masses of mature adipocytes within subcutaneous tissue, but can also be poorly circumscribed uncommonly. Cells show no pleomorphism, and are mature, white fat cells.
Conventional Lipoma
Fibrolipoma
Angiolipoma
Spindle Cell Lipoma
Myelolipoma
Pleomorphic Lipoma
Rearrangements are common.