Background: Ductal carcinoma in situ (DCIS) accounts for nearly 20% of new breast cancer diagnoses and ductal carcinoma in situ with microinvasion (DCIS-MI) is found in 5% to 10% of DCIS. Controversy exists regarding the appropriate local treatment as well as whether or not examination of the axilla should be performed either by sentinel lymph node biopsy (SLNB), axillary lymph node dissection (ALND) or not at all.
Methods: A MEDLINE search was performed using the keywords ductal carcinoma in situ and microinvasion. Recent articles pertaining to the definition and characterization of DCIS-MI as well as treatment and prognosis were analyzed.
Conclusions: The data at this time demonstrate no survival benefit for patients undergoing mastectomy versus lumpectomy and radiation. Numerous studies demonstrate axillary lymph node involvement to be as high as 20% with DCIS-MI; therefore, we believe that axillary sampling is essential. We recommend SLNB, which is accurate, provides information necessary for staging and treatment, and is associated with less morbidity than traditional ALND.