Gynaecomastia-like change of a female breast with tri-layer ductal epithelium as described in the male breast

A 31-year-old female presented with asymmetrical fullness in the right breast and was found to have a large span of fibrocystic change and nodular glandular tissue on magnetic resonance imaging. Breast malignancy could not be excluded, and thus excisional biopsy was performed. Histopathology revealed a rare finding of gynaecomastia-like histopathological changes of a female breast. Gynaecomastia is traditionally a clinical condition affecting the male breast and characterized by ductal hyperplasia, periductal fibrosis and oedema of the tissue. We describe the first finding of gynaecomastia-like change with a tri-layer ductal epithelium in a female breast, as previously described in the male breast.