Lipomas are the most common soft tissue tumor (benign or malignant).
One of several distinct benign lipomatous tumors. In its most conventional (simple) form, lipomas are composed of mature adipose tissue, typically enveloped by a well-defined thin fibrous capsule.
Not distinguishable histologically from normal adipose tissue
Several non conventional forms of lipomas (less commonly encountered) have been described, which may present in multiple locations, contain varying amounts of both adipose and non adipose tissue, and/or have more atypical cytologic features.
These non conventional variants include chondroid lipoma, myolipoma, lipoblastoma, angiolipoma, spindle cell lipoma/ pleomorphic lipoma, intramuscular/ intermuscular lipoma, lipoma of tendon sheath and joint, lipoma arborescens, lipomatosis of nerve, diffuse lipomatosis, multiple symmetric lipomatosis, adiposis dolorosa, and hibernoma.
Typically slow growing, superficial (subcutaneous), and asymptomatic; less commonly presents as a painful (angiolipoma) or deep-seated lesion
May present as an infiltrative lesion (cellular angiolipoma, diffuse lipomatosis, multiple symmetric lipomatosis (Madelung disease), and adiposis dolorosa (Dercum disease)
Often found in the upper trunk, especially the shoulders, back, neck, and head; but can be found anywhere in the body
Lipomas have been reported in anatomic locations as varied as cardiac, intrathoracic, endobronchial, retroperitoneal, breast, calf, thigh, scapular, intraosseous, fingers, palmar, toe, epidural, spinal, intra-articular (knee), parapharyngeal, nasopharyngeal, adrenal, inguinal, bladder, scrotal, ovarian, intracranial, intraneural, and GI tract (most often in the ileum).
Lipomas can cause respiratory distress due to bronchial obstruction of major airways, GI obstruction or bleeding, neuropathic symptoms from compression in locations such as the forearm or ankle, or cord compression if in dural/medullary components of the spinal cord.
Must be differentiated from other tumors, particularly liposarcomas, as treatment protocols.