Encapsulated papillary carcinoma of the breast: An institutional case series and literature review

Abstract Background Encapsulated papillary carcinoma of the breast is rare, making difficult diagnosis and resulting in patients undergoing excision biopsy before definitive surgery. Evidence‐based guidelines are sparse. We would like to further elucidate the clinicopathological, treatment and survival outcomes. Materials and Methods 54 patients identified, with a median follow up duration of 48 months. Patients' demographics, radiological and clinicopathological characteristics, treatment, adjuvant therapies as well as survival data were analysed. Results 18 (33.3%) cases were pure EPC, 12 (22.2%) were EPC associated with ductal carcinoma in situ (DCIS) and 24 (44.4%) cases had concurrent invasive ductal carcinoma. EPCs were more likely to present as a solid‐cystic mass on sonography (63.8%), regular‐shaped (oval or round) (97.9%), lack spiculations (95.7%) and lack suspicious microcalcifications (95.6%). Median tumour size was largest in the EPC with IDC group (18.5 mm). 2 patients developed loco‐regional recurrence. Overall survival is good for EPCs of all subtypes. Conclusion EPC is a rare tumour with excellent prognosis.