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.

简介： 乳腺粘液囊肿样病变 (MLL) 是一种罕见的实体，被认为具有不确定的恶性潜能。目前的英国指南建议对所有此类病变进行真空辅助切除 (VAE)，无论它们是否显示上皮异型性。本研究旨在回顾 MLL 的关键组织学和放射学特征，并根据上皮异型性的存在比较它们的不同结果。

方法：回顾性检索单个乳腺癌筛查中心的病理学记录，以查找 11 年期间所有活检诊断的 MLL。通过回顾初始核心活检的组织学并与相应的切除标本进行比较来计算恶性肿瘤的升级率（阳性预测值）。同时审查放射图像以提供放射病理学相关性。

结果：11 例活检非典型 MLL 患者中有 3 例 (27.3%) 在切除时出现恶性结果，而 36 例非典型 MLL 患者中只有 1 例 (2.8%)。大多数 MLL (93%) 在乳腺 X 线成像中被确定为微钙化。没有特定的放射学特征可以预测恶性肿瘤。

结论：我们的数据表明，没有非典型性的 MLL 可能会被当前方案过度治疗，并且可以通过放射学随访进行保守治疗。放射病理学相关性是必不可少的。