Appendicular Soft-Tissue Sarcoma — Classification, Resection and Radiotherapy
DNB Orthopaedics • October 2024 • Paper III • 10 Marks
Introduction
Soft-tissue sarcomas (STS) are malignant mesenchymal tumours arising from non-epithelial extraskeletal tissues such as muscle, adipose tissue, fibrous tissue, vessels and peripheral nerve sheaths.
Appendicular soft-tissue sarcomas commonly occur in the extremities, particularly the thigh. Modern treatment aims to achieve local tumour control and preservation of a functional limb using limb-salvage surgery, usually combined with radiotherapy when indicated.
Core oncological principle
Biopsy must be planned as part of the definitive operation: the biopsy tract should lie within the future resection specimen and must not contaminate uninvolved compartments or neurovascular structures.
A. Classification of Appendicular Soft-Tissue Sarcoma
Classification can be described according to histological lineage and according to oncological stage.
1. Histological Classification
| Lineage | Important Examples |
|---|---|
| Adipocytic | Liposarcoma |
| Fibroblastic / myofibroblastic | Fibrosarcoma, myxofibrosarcoma |
| Smooth muscle | Leiomyosarcoma |
| Skeletal muscle | Rhabdomyosarcoma |
| Vascular | Angiosarcoma |
| Peripheral nerve sheath | Malignant peripheral nerve sheath tumour — MPNST |
| Uncertain differentiation | Synovial sarcoma |
| Undifferentiated sarcoma | Undifferentiated pleomorphic sarcoma |
Enneking / Musculoskeletal Tumor Society Staging
For exam purposes, appendicular soft-tissue sarcoma may also be staged using the Enneking system, which considers:
- G — Histological grade
- T — Local…