Gynecomastia-like Lesion of the Female Breast

Definition

Lesion of the female breast formed by increased ducts and prominent stroma, histologically identical to gynecomastia of the male breast

Displays features typical of gynecomastia of the male breast
- Poorly circumscribed
- Ductal hyperplasia with micropapillae
  - Thin tips, wider at base
  - Smaller, hyperchromatic cells at tip but not at base
- Periductal stromal edema or fibrosis may be present
- No lobules
Reported sizes range from two high power fields to 5 cm
Gynecomastia-like change has been suggested to fall within the spectrum of fibrocystic disease
- It is frequently associated with fibrocystic disease
It has been variously designated as gynecomastia-like lesions, areas, changes and hyperplasia
- Some such distinctions are based on the presence of a mass, size and association with other processes
- We do not make such distinctions

Richard L Kempson MD
Robert V Rouse MD
Department of Pathology
Stanford University School of Medicine
Stanford CA 94305-5342