Ductal carcinoma in situ on core needle biopsy only with no residual disease at surgery.

Despite the minimal extent of disease exhibited in these cases, 6% of patients with DCIS on CNB only had IBTR at a median follow-up of 4 years. These data suggest that even minimal DCIS represents a significant risk of recurrence to the patient. Size and margins are not sufficient criteria to stratify risk and guide decisions for adjuvant therapies.