Sentinel lymph node biopsy reveals a positive popliteal node in clear cell sarcoma.

Clear cell sarcoma of the tendons and aponeuroses is an aggressive, rare soft tissue tumor with frequent metastases to regional lymph nodes. Sentinel lymph node biopsy, which has dramatically changed the management of melanoma, was used for clear cell sarcoma for an evaluation of popliteal and groin lymph node status. Although all isosulfan blue-stained groin lymph nodes were negative for malignancy, a popliteal lymph node was positive. Adjuvant 50 Gy of radiotherapy to the popliteal node might have been effective for local control for one year.