Sentinel node biopsy in pediatric soft tissue sarcomas of extremities.

Background: Sentinel Node Biopsy is an established staging technique in many adult malignancies. However, only few reports describe this procedure for the evaluation of regional lymph nodes in childhood and adolescents. Our experience with sentinel node biopsy in soft tissue sarcomas of extremities in children is reported.

Methods: Seventeen children were evaluated with sentinel node biopsy between 2002 and 2007: 11 at initial surgery, 5 at primary re-excision, 1 at local relapse. The diagnosis was rhabdomyosarcoma in 5 and other soft tissue sarcomas in 12: Ewing/PNET sarcoma 6, epithelioid sarcoma 1, malignant peripheral-nerve-sheath tumor 1, undifferentiated sarcoma 1, myxoid liposarcoma 2, adult-type fibrosarcoma 1. Primary sites included lower limbs (8), upper limbs (9). Mapping of nodes was performed with lymphoscintigraphy plus intra-operative injections with blue-dye in 14 cases, with lymphoscintigraphy and intra-operative injections alone in 2 and 1, respectively.

Results: Of the 17 lymphatic regions (9 axilla, 8 inguinal), 16 were identified with lymphoscintigraphy, 15 by intra-operative injections. Thirty-five lymph nodes were removed. Nodes were positive for metastasis in two patients with alveolar rhabdomyosarcoma and undifferentiated sarcoma. There were no complications. No further lymph node metastases were recognized either at diagnosis or during the follow-up (6-78 months).

Conclusions: Sentinel node biopsy was technically feasible, reliable, and free of complications. It could be an alternative to aggressive or random biopsies for extremity rhabdomyosarcoma and it can contribute to define those non-rhabdomyosarcoma soft tissue sarcomas that spread to regional nodes.