Early apocrine change in hyperplastic cystic disease.

Biopsy material from 42 cases of florid hyperplastic cystic disease of the breast were reviewed and were found to have foci of apocrine metaplasia. This appearance was limited to the ductular epithelium of hyperplastic lobules. It is believed that this scattered change is an initial feature in relation to the genesis of apocrine-lined and fully developed cysts.