+ General Considerations

  • Uncommon malignant tumor of adipose tissue
  • No breed or sex predilection
  • Liposarcoma does not arise from malignant transformation of lipoma
  • Liposarcoma associated with type-C virus particles in cats (i.e., retroviral infection) and reported secondary to glass foreign body in a dog
  • Sites: subcutaneous tissue (axial or appendicular), visceral (spleen and liver), and skeletal
  • Liposarcomas can infiltrate into veins, lymphatics, and underlying muscle

+ Biologic Behavior

Aggressive and locally invasive ± metastasis to lungs, liver, and bone

+ Prognosis

  • Guarded to good
  • 28% (12/43) local tumor recurrence with 83% (10/12) of these occurring in dogs with marginal excision
  • Metastatic rate < 10%
  • MST 694 days
  • Surgical dose is the only prognostic factor for survival with MST for incisional biopsy 183 days, 649 days for marginal excision, and 1,188 days for wide excision
  • However, MST for tumor size < 4 cm is 961 days and ≥ 4 cm is 612 days
  • Metastatic predictors in humans: histologic grade and tumor size
  • See Soft Tissue Sarcoma for more information