Introduction and objectives: Soft tissue sarcomas are rare mesenchymal neoplasms that constitute less than 10% of all pediatric malignancies. Half of these are rhabdomyosarcomas, the remaining 50% have a varied and heterogenous histologic and clinical patterns (fibrosarcoma, synovial cell sarcoma, extraskeletal Ewing's sarcoma, angiosarcoma, liposarcoma, leiomyosarcoma, ...). The purpose of this work is to evaluate our clinical experience with soft tissue sarcomas in uncommon sites over the past 10 years in order to delimitate the prognostic factors in survival and modalities of treatment.
Material and methods: Between 1989 and 1998, 10 patients were diagnosed with soft tissue sarcomas in uncommon sites and treated by us over a total number of 139 pediatric neoplasms (7.19%). Data on these patients were obtained from careful review of medical records. Variables investigated included histologic findings, tumor size, age at presentation, primary site, clinical group, radiologic test performed, surgical treatment, radiotherapy and adjuvant chemotherapy, complications and survival rates. Charts were registered in database Access. Statistical analysis was performed by the SPSS 8.0 statistical program.
Results: The following histologic types of these 10 tumors were identified: 1 hemangiopericytoma in oral cavity, 2 extraosseous Ewing's sarcoma, 1 botryoid rhabdomyosarcoma of the bladder, 1 mediastinal fibrosarcoma, 1 retroperitoneal rhabdomyosarcoma, 1 paratesticular rhabdomyosarcoma, 1 cervical condrosarcoma, 1 alveolar rhabdomyosarcoma and 1 deltoid rhabdomyosarcoma. 50% were rhabdomyosarcomas and the remaining 50% have a variated sarcomatous histologic pattern with a difficult classification. The mean age at diagnosis was 7 years (4.6 years accounted for rhabdomyosarcoma alone). Surgery with complete excision were performed only in six cases. Adjuvant chemotherapy with IVA was followed by radiotherapy only in four patients. All the children classified in clinical groups II, III or IV needed 2nd. line regimens of chemotherapy. Three patients died in the follow-up instead of the multimodal treatment. Survival ranged from 6 months to 9 years (mean 4 years).
Conclusions: The impact of surgical resectability on outcome in these tumors has been clearly demonstrated over other factors like histologic appearance. Distant metastasis are infrequent but local recurrence are a constant in all cases with incomplete surgical resection. Based on those facts we could advanced an adequate approach to this kind of neoplasms: 1) wide complete surgical resection is mandatory; 2) radiotherapy will only be necessary if margins of resection cannot control the local disease, and 3) chemotherapy have not clearly demonstrated his benefits as adjuvant therapy in clinical group I lesions but his employ is recommended in all cases because of the poor prognosis due to local recurrence.