Background: The incidence of breast ductal Carcinoma in Situ (DCIS) has been increasing; it currently represents up to 20-25% of all breast carcinomas. Encysted papillary cancer (EPC) is a rare form of breast carcinoma previously compared to DCIS which has been shown to present histologically with invasion of the basement membrane and even metastasis. Aims: Our objective was to define a ‘high risk’ group of patients with pre-op diagnosis of noninvasive cancer undergoing breast conserving surgery (BCS), who would then benefit from SLNB. Methods: A retrospective data collection including all the patients with DCIS over the last 5 years was performed. High risk was defined as: Extensive micro-calcification >40mm or any mass forming DCIS. EPC patients were collected via a Winpath search.