Mucocele-like Lesions of the Breast: Mammographic, Sonographic, and Pathologic Findings and Upgrade Rate

Full Article

HHC Tsang, JWC Wai, JLF Chiu, OK Wong

Hong Kong J Radiol 2016;19:279-86

DOI: 10.12809/hkjr1615330

Objective: To describe the mammographic, sonographic, and pathologic appearance of mucocele-like lesions (MLLs) of the breast and to determine the upgrade rate following surgical excision.

Methods: All patients who attended Queen Elizabeth Hospital, Hong Kong from 1 January 2008 to 31 May 2014 with core needle biopsies (CNB) and MLL as one of the final pathological diagnoses or with mucinous material found within the specimens were identified. All available breast imaging, and pathology slides and reports were reviewed by radiologists and a pathologist specialised in breast imaging, respectively. The upgrade rate of MLL to high-risk lesion or to malignancy was obtained.

Results: Twelve patients had either MLL or mucinous material within their CNB specimen. Their mean age was 47 years (range, 31-77 years). The most common mammographic finding was grouped coarse heterogeneous calcifications (56%) and the most observed feature on ultrasound was lesions containing cystic components (71%). Of the 12 patients, six subsequently underwent excisional biopsy of their lesion. One of them had atypia shown on CNB and a final surgical specimen revealing MLL associated with ductal carcinoma in-situ. Of the five patients with CNB showing no atypia, three (60%) were upgraded — upgraded histology included one node-negative papillary carcinoma with foci of mucinous carcinoma and two with high-risk histology of atypical ductal hyperplasia.

Conclusion: MLLs of the breast have variable mammographic and sonographic appearances but the common radiological findings include presence of grouped heterogeneous calcifications mammographically and lesions containing cystic components sonographically. A significant proportion of lesions that yielded mucinous material or that were diagnosed as a MLL on percutaneous CNB without atypia were upgraded. Surgical excision is still warranted following a CNB diagnosis of MLL to allow evaluation of the entire area and to exclude the presence of atypia or carcinoma.


Authors’ affiliations:
HHC Tsang, JWC Wai, JLF Chiu: Department of Radiology and Imaging, Queen Elizabeth Hospital, Jordan, Hong Kong
OK Wong: Department of Pathology, Queen Elizabeth Hospital, Jordan, Hong Kong