Mucocele-like lesions of the breast - A radiological and clinicopathological analysis

Abstract

Introduction: Mucocele-like lesions (MLL) of the breast are rare entities which are considered to harbor uncertain malignant potential. Current UK guidelines recommend vacuum assisted excision (VAE) of all such lesions regardless of whether they display epithelial atypia. This study sought to review the key histological and radiological features of MLLs and compare their differing outcomes based on the presence of epithelial atypia.Methods: Pathology records of a single breast cancer screening center were retrospectively searched for all biopsy diagnosed MLLs over an 11-year period. Upgrade rates to malignancy (positive predictive values) were calculated by reviewing histology from the initial core biopsy and comparing with the corresponding excision specimen. Radiological images were simultaneously reviewed to provide radiological-pathological correlation.Results: Three of 11 patients (27.3%) with atypical MLLs on biopsy had malignant outcomes at excision, compared with only 1 of 36 patients (2.8%) with non-atypical MLLs. The majority of MLLs (93%) were identified as microcalcifications on mammographic imaging. No specific radiological features were predictive of malignancy.Conclusions: Our data suggest that MLLs without atypia are potentially overtreated with current protocols and could be managed conservatively with radiological follow up. Radiological-pathological correlation is essential.