Sentinel Lymph Node Biopsy in Intraductal Carcinoma of the Breast with Microinvasion

Abstract

Ductal carcinoma in situ with microinvasion (DCISM) is a separate clinical and pathological entity, distinct from pure ductal carcinoma in situ (DCIS), with a low but well-known metastatic potential. Due to the low rate of axillary metastases in DCISM, there is controversy regarding the indication for complete axillary dissection (CAD) to stage the axilla. Sentinel lymph node biopsy (SNLB) could be routinely proposed to accurately stage the axilla avoiding the morbidity of a CAD. From March 1996 to December 2002, out of 4602 SLNBs performed for invasive carcinoma of the breast, 41 patients with DCISM in the definitive diagnosis were selected. Metastasis in the SLN were detected in 4 of 41 (9.7%) patients. Two of the 4 patients had only micrometastasis in the SLN. In three of these patients, the SLN was the only positive node after CAD. SLN biopsy should be considered as a standard procedure in DCISM patients. Complete AD may not be mandatory if only the SLN contains micrometastatic disease.