Cellular Classification of Adult Soft Tissue Sarcoma

Soft tissue sarcomas are classified histologically according to the soft tissue cell of origin, though the cell type is not part of the prognostic staging system. Additional studies, including electron microscopy, histochemistry, flow cytometry, cytogenetics, and tissue culture studies may allow identification of particular subtypes within the major histologic categories.

The histologic grade reflects the metastatic potential of these tumors more accurately than the classic cellular classification listed below.[1-3] Overall, malignant fibrous histiocytoma is the most common histologic type (40% of the total) followed by liposarcoma (25%); however, frequency of histologic type is site-dependent. Pathologists assign grade based on the number of mitoses per high-powered field, presence of necrosis, cellular and nuclear morphology, and the degree of cellularity; discordance among expert pathologists can reach 40% on prospective review.[3,4]

• Alveolar soft-part sarcoma.[5]
• Angiosarcoma.[6-8]
• Dermatofibrosarcoma protuberans.[9]
• Epithelioid sarcoma.
• Extraskeletal chondrosarcoma.
• Extraskeletal osteosarcoma.
• Fibrosarcoma.
• Gastrointestinal stromal tumor (GIST). (Refer to the PDQ summary on Gastrointestinal Stromal Tumors Treatment ¹ for more information.)
• Leiomyosarcoma.
• Liposarcoma.
• Malignant fibrous histiocytoma.
• Malignant hemangiopericytoma.
• Malignant mesenchymoma.
• Malignant schwannoma.
• Malignant peripheral nerve sheath tumor.
• Peripheral neuroectodermal tumors.
• Rhabdomyosarcoma. (Refer to the PDQ summary on Childhood Rhabdomyosarcoma Treatment ² for more information.)
• Synovial sarcoma.
• Sarcoma, NOS (not otherwise specified).

References

1. Marcus SG, Merino MJ, Glatstein E, et al.: Long-term outcome in 87 patients with low-grade soft-tissue sarcoma. Arch Surg 128 (12): 1336-43, 1993.  [PUBMED Abstract]
   
   
2. Soft tissue sarcoma. In: American Joint Committee on Cancer.: AJCC Cancer Staging Manual. 6th ed. New York, NY: Springer, 2002, pp 193-7. 
   
   
3. Gaynor JJ, Tan CC, Casper ES, et al.: Refinement of clinicopathologic staging for localized soft tissue sarcoma of the extremity: a study of 423 adults. J Clin Oncol 10 (8): 1317-29, 1992.  [PUBMED Abstract]
   
   
4. Alvegård TA, Berg NO: Histopathology peer review of high-grade soft tissue sarcoma: the Scandinavian Sarcoma Group experience. J Clin Oncol 7 (12): 1845-51, 1989.  [PUBMED Abstract]
   
   
5. van Ruth S, van Coevorden F, Peterse JL, et al.: Alveolar soft part sarcoma. a report of 15 cases. Eur J Cancer 38 (10): 1324-8, 2002.  [PUBMED Abstract]
   
   
6. Fury MG, Antonescu CR, Van Zee KJ, et al.: A 14-year retrospective review of angiosarcoma: clinical characteristics, prognostic factors, and treatment outcomes with surgery and chemotherapy. Cancer J 11 (3): 241-7, 2005 May-Jun.  [PUBMED Abstract]
   
   
7. Abraham JA, Hornicek FJ, Kaufman AM, et al.: Treatment and outcome of 82 patients with angiosarcoma. Ann Surg Oncol 14 (6): 1953-67, 2007.  [PUBMED Abstract]
   
   
8. Fayette J, Martin E, Piperno-Neumann S, et al.: Angiosarcomas, a heterogeneous group of sarcomas with specific behavior depending on primary site: a retrospective study of 161 cases. Ann Oncol 18 (12): 2030-6, 2007.  [PUBMED Abstract]
   
   
9. Mendenhall WM, Zlotecki RA, Scarborough MT: Dermatofibrosarcoma protuberans. Cancer 101 (11): 2503-8, 2004.  [PUBMED Abstract]