[Six Cases of Encapsulated Papillary Carcinoma of the Breast]

Encapsulated papillary carcinoma(EPC)is a rare malignant papillary lesion newly classified as ⅠB by the World Health Organization in 2012. We report 6 cases of EPC experienced at our hospital. The median age of the patients was 71.5 years. The main complaint was mass in 4 cases. Mammography was category 3 or higher in all cases. Ultrasound revealed 4 cases of solid mass and 2 cases of mixed mass. Fine needle aspiration biopsies were performed in 2 cases, one of which was malignant. Excisional biopsies were performed in 3 cases, all of which were diagnosed with EPC. Mastectomy was performed in 2 patients and partial mastectomy was performed in 4 patients. Pathological findings revealed invasion in 1 patient and 4 patients were hormone receptor-positive. Human epidermal growth factor receptor 2 of invasive case was negative. Partial resections were treated with radiation:only invasive case was treated with endocrine therapy. Rapid growth and high proliferative activity was noted in patients with invasive EPC;this suggests the need to carefully monitor the prognosis of such patients.