There are 5 soft tissue tumor classifications (WHO):
- Well-differentiated (sclerosing, inflammatory, and adipocytic) – Also called atypical lipomatous tumor; includes well-differentiated spindle-cell liposarcoma.
- Dedifferentiated or transitioning
- Myxoid – Intramuscular thigh is the most common location.
- Pleomorphic – Usually on extremities or the trunk.
- Mixed type – Myxoid and well-differentiated or dedifferentiated liposarcoma or myxoid and pleomorphic liposarcoma.
C49.9 – Malignant neoplasm of connective and soft tissue, unspecified
254828009 – Malignant lipomatous tumor