This is fibrocystic disease of the breast. It is benign. Note that there are fibrosis and cysts in the breast. On microscopic exam you would see flattened epithelium with varying degrees of cellular atypia. On clinical exam this disease presents as a lumpy breast with midcycle tenderness. It is the most common disorder of the breast, and the most common cause of a palpable breast mass in women between the ages of 25 and 50. It is uncommon before adolescence or after menopause.
