Mucocele-like lesions of the breast: a clinical outcome and histologic analysis of 102 cases.

Mucocele-like lesions (MLLs) of the breast are characterized by cystic architecture with stromal mucin and frequent atypia, but it is unknown whether they convey long-term breast cancer risk. We evaluated 102 MLLs that were derived from a single-institution benign breast disease cohort of 13412 women who underwent biopsy from 1967 to 2001. MLLs were histologically characterized by type of lining epithelium, architecture of the lesion, associated atypical hyperplasia (AH), and incidence of breast cancer (14.