The mammographic appearances of benign mammary mucocele-like lesions

Mucocele-like lesions of the breast were first described in the pathology literature in 1986. No series of the mammographic appearances of these lesions has been described. These benign breast lesions are composed of minute multiple cysts lined by uniform flat or cuboidal to columnar epithelium. Microscopically, microcalcifications are frequently present within the cysts and extravasated mucus. These lesions may mimic the microcalcifications of ductal carcinoma in situ at screening mammography.

Method

A review of the multidisciplinary breast clinic database revealed 20 cases of mammary mucocele-like lesion diagnosed at Royal Perth from January 1996 to December 2001.

Results

All lesions presented as impalpable mammographic screen detected lesions. Nineteen lesions presented as clusters of irregular calcification mimicking ductal carcinoma; one lesion presented as a complex cystic mass at mammography and ultrasound. Fine needle aspiration yielded mucinous material. Core biopsy confirmed mucocele-like lesion in 15 lesions. Seventeen women underwent open biopsy following hook-wire localisation.

Discussion

Mammary mucocele-like lesions are rare screen detected lesions that may calcify and mimic ductal carcinoma in situ or present as complex cystic masses. Fine needle aspiration of mucinous carcinoma and mucocele-like lesions may yield mucin with scant epithelium. Core biopsy or excisional biopsy is recommended to differentiate between these lesions.