Axillary node dissection in ductal carcinoma in situ.

Intraductal carcinoma of the breast has become a well-defined entity that has been more frequently diagnosed since the introduction of mammography. For many years, the usual treatment has been mastectomy, often with axillary lymph node dissection. Concurrent with documentation that breast conservation treatment has been effective for many invasive breast cancers, such treatment has been introduced for noninvasive breast cancers (ductal carcinoma in situ and lobular cancer in situ). However, there is no basis for axillary dissection because tumor cells are contained by the basement membrane and should not metastasize. In this study, 107 axillary dissections were carried out, with an average of 20 nodes identified, and a single metastasis was identified.