New lessons from the sentinel node

Sentinel node biopsy to determine the presence of metastatic disease in regional lymph nodes has been described in a variety of solid tumors. Sentinel node biopsy has proven that drainage of cancer cells to the regional lymph nodes is an orderly process with metastasis predominantly to one or two nodes first before involvement of subsequent nodes. The use of this technique has resulted in the increased identification of regional metastasis suggesting that patients previously identified as node negative may have unidentified regional metastasis. The clinical significance of these microscopic tumor deposits in lymph nodes remains controversial.