Frozen section diagnosis for axillary sentinel lymph nodes: the first six years.

Intraoperative frozen section of axillary lymph nodes for the detection of metastatic breast cancer has been controversial because of the labor-intensive techniques necessary to obtain a highly sensitive test, and because of the uncertain significance of frequently detected submicrometastatic carcinoma. In total, 874 consecutive axillary sentinel lymph node cases examined by intraoperative frozen section over a 6-year period were reviewed retrospectively. Frozen section had a sensitivity of 60% and was 100% specific, but when cases with submicrometastatic tumor cells were considered negative, the sensitivity rose to 83%. Rare cases were called 'atypical' on frozen section; almost all of these cases were negative for carcinoma on permanent sections.