Soft Tissue Tumors

Lipoma

• Introduction
  • most common benign soft tissue tumor in adults
  • soft, well-encapsulated fat tumor
• Differential diagnosis
  • ganglion cysts
    • synovial herniation over underlying tendon sheath or joint 
    • dorsal wrist commonly affected, but volar wrist can also be affected
    • asymptomatic, painless
    • transilluminates with light
      • distinguishes ganglion cysts from solid masses such as lipomas
• Treatment
• simple excision typically curative

Liposarcoma

• Introduction
  • most common malignant soft tissue tumor in adults
  • malignant fat tumor that can be large
• Evaluation 
  • lipoblast is the characteristic cell
• Treatment
• will recur without full excision

Rhabdomyoma

• Introduction
  • benign tumor derived from striated muscle (skeletal or cardiac)
    • most common cardiac tumor in children 
  • associated conditions
    • tuberous sclerosis 
• specifically rhabdomyoma of the heart

Rhabdomyosarcoma

• Introduction
  • most common malignant soft tissue tumor of childhood
  • arises from skeletal muscle
  • typically involves head/neck, vagina
• Evaluation
  • rhabdomyoblast is characteristic cell
    • desmin positive stains