Fat Necrosis

Fat Necrosis (Breast)

Etiology

• Phagocytosis of necrotic adipose cells

• Most common cause is trauma (MVC etc.)

• Can be seen with duct ectasia that has ruptured (may have apocrine metaplasia present)

Clinical picture

• Trauma to breast then patient has a localized, firm area with eventual scarring & calcifications.

Histologic Findings

Histologic Findings:

• Consists of necrotic adipocytes, fibrosis and inflammation

  • Irregular steatocytes with loss of peripheral nuclei

  • Pink amorphous necrotic material/debris

  • Inflammatory cells

    • Foamy (lipid-laden) macrophages

    • +/- Foreign body giant cells

    • Neutrophils/lymphocytes/plasma cells

    • BEWARE: Reactive fibroblasts and reactive endothelial cells can look ugly and can be confused with carcinoma!!