What constitutes adequate study of axillary lymph nodes in breast cancer?

This study was undertaken to determine the value of the clearing technique and multilevel sectioning of lymph nodes to aid in optimally examining axillary dissections for lymph node metastases. One hundred consecutive mastectomy specimens with axillary dissections were initially examined by our routine technique: examination of fat for lymph nodes by inspection and palpation and examination of one microsection from each lymph node. The remaining axillary tissue was then cleared using the technique of Durkin and Haagensen and each of the originally examined lymph nodes was resectioned at two additional deeper levels. In our routine examination, 2203 lymph nodes were found with 211 lymph nodes containing metastatic tumor. Clearing disclosed 412 additional lymph nodes, of which 17 contained metastatic tumor. The two additional microsections of lymph nodes revealed tumor in only two lymph nodes which were initially free of tumor. The extended study of the axilla did not add significantly to our routine examination.