LAUSR

Nipple adenoma (NA) is a rare benign epithelial tumour occurring in the nipple. Histologically, it exhibits variable and often mixed adenosis‐like and usual ductal hyperplasia‐like growth patterns. Morphologically, it is similar to other benign proliferative breast lesions occurring in the breast parenchyma, which have been shown to harbour activating mutations in PIK3CA, AKT1 or, less frequently, in RAS in more than 50% of cases. In this study, we aimed to analyse the mutation status of PIK3CA, AKT1, RAS and BRAF in NAs and correlated the mutation status with the histological features.