TATISTICAL studies have shown that far S fewer patients survive 5 years after radical mastectomy for cancer when metastases are found in the axillary lymph nodes than when no metastases are found.1, 2, 7 However, patients without lymph node metastases also die of cancer. T h e discovery of hidden or occult axillary metastases might reveal the biologically malignant nature of the tumor and explain some of these deaths. If so, a more detailed pathological study of the surgical specimen should be of value in revealing their presence. Studies have been carried out, and occult metastases were found in a high percentage of so-called "negative" specimen^.^,
The finding of occult metastases per se, however, does not necessarily mean that the entire explanation of the occasional death in this favorable group has been found. Clinical and pathological correlations must be analyzed to reveal the actual significance of these occult metastases. This report concerns such a study.
MATERIAL AND METHOD
A series of 202 consecutive mammary specimens obtained at operation were studied. In 199 cases the operation included radical resection of the axillary lymph nodes. All of these latter cases are incorporated in the study.
T h e regional lymph nodes were located by clearing the lymph node-bearing tissue.4 One microscopic section from each of the isolated lymph nodes was searched for metastases. I n about one-half of those specimens without axillary lymph node metastases detectable by study of the routine sections, the lymph node tissue remaining in the blocks was serially