Soft tissue sarcomas are a rare and heterogeneous group of tumors that arise from mesenchymal tissues. They account for less than 1% of adult cancers and 7% of childhood cancers. The most common types in adults are malignant fibrous histiocytoma, leiomyosarcoma, and liposarcoma. Treatment involves surgical resection with negative margins, often combined with radiation therapy. For high-risk localized or metastatic disease, chemotherapy may also be used. Accurate diagnosis and treatment planning by a multidisciplinary team is important for managing these rare tumors.

1. Soft Tissue Sarcomas

4. INTRODUCTION: Incidence Sarcomas are a heterogeneous group of tumors that arise predominantly from the embryonic mesoderm, but also can originate, as does the peripheral nervous system, from the ectoderm.

9. Relative Frequency of Histologic Subtypes of Soft Tissue Sarcoma Histologic Subtypes n % Malignant fibrous histiocytomaxs 349 28 Liposarcoma 188 15 Leiomyosarcoma 148 12 Unclassified sarcoma 140 11 Synovial sarcoma 125 10 Malignant peripheral nerve sheath tumor 72 6 Rhabdomyosarcoma 60 5 Fibrosarcoma 38 3 Ewing's sarcoma 25 2 Angiosarcoma 25 2 Osteosarcoma 14 1 Epithelioid sarcoma 14 1 Chondrosarcoma 13 1 Clear cell sarcoma 12 1 Alveolar soft part sarcoma 7 1 Malignant hemangiopericytoma 5 0.4

28. Initial Assessment

49. Excisional Biopsy Excisional biopsy can be performed for easily accessible (superficial) extremity or truncal lesions smaller than 3 cm. Excisional biopsy should not be done for lesions involving the hands and feet because definitive reexcision may not be possible after the biopsy. Excisional biopsy results have a 30 to 40% rate of recurrence when margins are positive or uncertain. Excisional biopsies rarely provide any benefit over other biopsy techniques and may cause postoperative complications that could ultimately delay definitive therapy.

54. American Joint Committee on Cancer Primary Tumor (T) T1 Tumor 5 cm T1a Superficial tumor T1b Deep tumor T2 Tumor >5 cm T2a Superficial tumor T2b Deep tumor Regional Lymph Nodes (N ) N0 No regional lymph node metastasis N1 Regional lymph node metastasis Distance Metastasis (M) M0 No distant metastasis M1 Distant metastasis Histologic Grade (G) G1 Well differentiated G2 Moderately differentiated G3 Poorly differentiated G4 Poorly differentiated or undifferentiated

55. Stage Grouping Stage I T1a, 1b, 2a, 2b N0 M0 G1–2 G1 Stage II T1a, 1b, 2a N0 M0 G3–4 G2–3 Stage III T2b N0 M0 G3–4 G2–3 Stage IV Any T N1 M0 Any G Any G Any T N0 M1 Any G Any G

63. Amputation Amputation is the treatment of choice for patients with the rare 5% of tumors that cannot be grossly resected with a limb-sparing procedure and preservation of function

77. Special Situations

87. Surgical-Pathologic Grouping of Soft Tissue Sarcoma Clinical Group Definition I a. Localized, completely resected, confined to site of origin b. Localized, completely resected, beyond site of origin II a. Localized, grossly resected microscopic residual tumor b. Regional disease, involved lymph nodes, completely resected c. Regional disease, involved lymph nodes grossly resected with microscopic residual tumor III a. Local or regional grossly visible disease after biopsy only b. Grossly visible disease after <50% resection of primary tumor IV Distant metastases at diagnosis

92. Research Perspectives