Mucocele-like Lesions of the Breast.

Mucocele-like lesions of the breast (MLL) are believed to be due to mucinous ducts extruding their contents into the surrounding stroma. MLLs are a rare entity usually identified by calcifications noted on routine screening mammography. Surgical excision has been recommended due to the propensity for these lesions to harbor atypical ductal hyperplasia (ADH) or malignancy. A 44-year-old female patient presented to the breast center after undergoing routine mammography which showed a group of coarse appearing microcalcifications in the outer third of the breast. After further workup, a core needle biopsy was obtained with pathology showing benign breast tissue with acellular stromal mucin pools containing dystrophic calcifications. The patient underwent surgical excision with final pathology revealing ductal carcinoma in-situ and ADH with prominent mucin production throughout the stroma.