NRSTSs are more common in adults  than in children; therefore, much of the information regarding the treatment and natural history of children with these lesions has been on the basis of findings from adult studies. Some pediatric NRSTSs are associated with a better outcome. This difference is most pronounced for infants and children younger than 4 years with fibrosarcoma, which is a locally aggressive but not metastatic tumor. These patients have an excellent prognosis given that the tumor is highly chemosensitive and surgery alone can cure a significant number of these patients.[4,11,12,13] Soft tissue sarcomas in older children and adolescents often behave similarly to those in adult patients.[4,14]
Although they can develop in any part of the body, NRSTSs arise most commonly in the trunk and extremities.[6,7,15] These neoplasms can present initially as an asymptomatic solid mass, or they may be symptomatic because of local invasion of adjacent anatomical structures. Systemic symptoms (e.g., fever, weight loss, and night sweats) are rare. Hypoglycemia and hypophosphatemic rickets have been reported in cases of hemangiopericytoma, whereas hyperglycemia has been noted in patients with fibrosarcoma of the lung.
Some genetic and environmental factors have been associated with the development of NRSTS. Heritable cancer-associated changes of the p53 tumor suppressor gene can occur in families with Li-Fraumeni syndrome. Members of these families have an increased risk of developing soft tissue tumors, bone sarcomas, breast cancer, brain tumors, and acute leukemia. Approximately 4% of patients with neurofibromatosis type 1 develop malignant peripheral nerve sheath tumors, which usually develop after a long latency; some patients develop multiple lesions.[18,19,20] Patients with familial adenomatous polyposis are at increased risk for developing desmoid tumors. Some NRSTSs (particularly malignant fibrous histiocytoma) can develop within a previously irradiated site; others (e.g., leiomyosarcoma) have been linked to Epstein-Barr virus infection in patients with AIDS.[4,22,23]
Synovial sarcomas are the most common NRSTSs reported in children. The most common location is the lower extremity followed by upper extremity, trunk, abdomen, and head and neck. Approximately 30% of patients with synovial sarcoma are younger than 20 years. The most common site of metastasis is the lung. Factors such as International Union Against Cancer/American Joint Committee on Cancer stage III/stage IVA, tumor necrosis, truncal locations, elevated mitotic rate, age, and histologic grade have been associated with a worse prognosis in adults.[25,26,27]
(Refer to the PDQ summary on Childhood Rhabdomyosarcoma Treatment for more information. Refer to the PDQ summary on Ewing Sarcoma Family of Tumors Treatment for more information on extraosseous Ewing, peripheral neuroepithelioma, and Askin tumors.)
The prognosis and biology of NRSTS tumors vary greatly depending on the age of the patient, the primary site, tumor size, tumor invasiveness, histologic grade, depth of invasion, and extent of disease at diagnosis. Because long-term related morbidity must be minimized while disease-free survival is maximized, the ideal therapy for each patient must be carefully and individually determined utilizing these prognostic factors before initiating therapy for these patients.[7,12,24,28,29,30]
- Smith MA, Seibel NL, Altekruse SF, et al.: Outcomes for children and adolescents with cancer: challenges for the twenty-first century. J Clin Oncol 28 (15): 2625-34, 2010.
- Guidelines for the pediatric cancer center and role of such centers in diagnosis and treatment. American Academy of Pediatrics Section Statement Section on Hematology/Oncology. Pediatrics 99 (1): 139-41, 1997.
- Pappo AS, Pratt CB: Soft tissue sarcomas in children. Cancer Treat Res 91: 205-22, 1997.
- Okcu MF, Pappo AS, Hicks J, et al.: The nonrhabdomyosarcoma soft tissue sarcomas. In: Pizzo PA, Poplack DG: Principles and Practice of Pediatric Oncology. 6th ed. Philadelphia, Pa: Lippincott Williams and Wilkins, 2010, pp 954-86.
- Weiss SW, Goldblum JR: General considerations. In: Weiss SW, Goldblum JR: Enzinger and Weiss's Soft Tissue Tumors. 5th ed. St. Louis, Mo: Mosby, 2008, pp 1-14.
- Dillon P, Maurer H, Jenkins J, et al.: A prospective study of nonrhabdomyosarcoma soft tissue sarcomas in the pediatric age group. J Pediatr Surg 27 (2): 241-4; discussion 244-5, 1992.
- Rao BN: Nonrhabdomyosarcoma in children: prognostic factors influencing survival. Semin Surg Oncol 9 (6): 524-31, 1993 Nov-Dec.
- Fletcher CD, Dal Cin P, de Wever I, et al.: Correlation between clinicopathological features and karyotype in spindle cell sarcomas. A report of 130 cases from the CHAMP study group. Am J Pathol 154 (6): 1841-7, 1999.
- Skytting BT, Bauer HC, Perfekt R, et al.: Clinical course in synovial sarcoma: a Scandinavian sarcoma group study of 104 patients. Acta Orthop Scand 70 (6): 536-42, 1999.
- Herzog CE: Overview of sarcomas in the adolescent and young adult population. J Pediatr Hematol Oncol 27 (4): 215-8, 2005.
- Weiss SW, Goldblum JR: Clinical evaluation and treatment of soft tissue tumors. In: Weiss SW, Goldblum JR: Enzinger and Weiss's Soft Tissue Tumors. 5th ed. St. Louis, Mo: Mosby, 2008, pp 15-31.
- Dillon PW, Whalen TV, Azizkhan RG, et al.: Neonatal soft tissue sarcomas: the influence of pathology on treatment and survival. Children's Cancer Group Surgical Committee. J Pediatr Surg 30 (7): 1038-41, 1995.
- Neville H, Corpron C, Blakely ML, et al.: Pediatric neurofibrosarcoma. J Pediatr Surg 38 (3): 343-6; discussion 343-6, 2003.
- Weiss SW, Goldblum JR: Enzinger and Weiss's Soft Tissue Tumors. 4th ed. St. Louis, Mo: Mosby, 2001.
- Zeytoonjian T, Mankin HJ, Gebhardt MC, et al.: Distal lower extremity sarcomas: frequency of occurrence and patient survival rate. Foot Ankle Int 25 (5): 325-30, 2004.
- Weiss SW, Goldblum JR: Miscellaneous tumors of intermediate malignancy. In: Weiss SW, Goldblum JR: Enzinger and Weiss's Soft Tissue Tumors. 5th ed. St. Louis, Mo: Mosby, 2008, pp 1093-1160.
- Chang F, Syrj�nen S, Syrj�nen K: Implications of the p53 tumor-suppressor gene in clinical oncology. J Clin Oncol 13 (4): 1009-22, 1995.
- Weiss SW, Goldblum JR: Benign tumors of peripheral nerves. In: Weiss SW, Goldblum JR: Enzinger and Weiss's Soft Tissue Tumors. 5th ed. St. Louis, Mo: Mosby, 2008, pp 825-901.
- deCou JM, Rao BN, Parham DM, et al.: Malignant peripheral nerve sheath tumors: the St. Jude Children's Research Hospital experience. Ann Surg Oncol 2 (6): 524-9, 1995.
- Stark AM, Buhl R, Hugo HH, et al.: Malignant peripheral nerve sheath tumours--report of 8 cases and review of the literature. Acta Neurochir (Wien) 143 (4): 357-63; discussion 363-4, 2001.
- Groen EJ, Roos A, Muntinghe FL, et al.: Extra-intestinal manifestations of familial adenomatous polyposis. Ann Surg Oncol 15 (9): 2439-50, 2008.
- Weiss SW, Goldblum JR: Malignant fibrous histiocytoma (pleomorphic undifferentiated sarcoma). In: Weiss SW, Goldblum JR: Enzinger and Weiss's Soft Tissue Tumors. 5th ed. St. Louis, Mo: Mosby, 2008, pp 403-27.
- McClain KL, Leach CT, Jenson HB, et al.: Association of Epstein-Barr virus with leiomyosarcomas in children with AIDS. N Engl J Med 332 (1): 12-8, 1995.
- Pappo AS, Fontanesi J, Luo X, et al.: Synovial sarcoma in children and adolescents: the St Jude Children's Research Hospital experience. J Clin Oncol 12 (11): 2360-6, 1994.
- Trassard M, Le Doussal V, Hac�ne K, et al.: Prognostic factors in localized primary synovial sarcoma: a multicenter study of 128 adult patients. J Clin Oncol 19 (2): 525-34, 2001.
- Guillou L, Benhattar J, Bonichon F, et al.: Histologic grade, but not SYT-SSX fusion type, is an important prognostic factor in patients with synovial sarcoma: a multicenter, retrospective analysis. J Clin Oncol 22 (20): 4040-50, 2004.
- Ferrari A, Gronchi A, Casanova M, et al.: Synovial sarcoma: a retrospective analysis of 271 patients of all ages treated at a single institution. Cancer 101 (3): 627-34, 2004.
- Marcus KC, Grier HE, Shamberger RC, et al.: Childhood soft tissue sarcoma: a 20-year experience. J Pediatr 131 (4): 603-7, 1997.
- Pratt CB, Pappo AS, Gieser P, et al.: Role of adjuvant chemotherapy in the treatment of surgically resected pediatric nonrhabdomyosarcomatous soft tissue sarcomas: A Pediatric Oncology Group Study. J Clin Oncol 17 (4): 1219, 1999.
- Pratt CB, Maurer HM, Gieser P, et al.: Treatment of unresectable or metastatic pediatric soft tissue sarcomas with surgery, irradiation, and chemotherapy: a Pediatric Oncology Group study. Med Pediatr Oncol 30 (4): 201-9, 1998.