Underestimation of invasive breast carcinoma in patients with initial diagnosis of ductal carcinoma in situ: Size matters.

Introduction: The aim of our study was to identify those patients with preoperative diagnosis of ductal carcinoma in situ (DCIS) and high risk of upstaging to invasive breast carcinoma (IBC), in whom sentinel lymph node biopsy (SLNB) should be considered.

Methods: One-hundred and five DCIS patients treated with breast-conserving surgery (BCS) or mastectomy were studied. Preoperative features of the tumors were analyzed to investigate its association with underestimation of IBC on final pathology.

Results: Overall, the underestimation rate of IBC was 16.2%. The underestimation rate was highest in lesions with initial size >2 cm compared with those with size ≤2 cm (26.8% vs. 4.1%, respectively; p < 0.003). Eighty-eight patients (83.8%) underwent concurrent SLNB and only one case had lymph node involvement (1.1%).

Conclusions: SLNB should be considered in DCIS patients receiving BCS with lesions greater than 2 cm since approximately one in four will harbor an IBC.