A 42-year-old woman presents with a firm, ill-defined breast mass three months after a seatbelt injury to the chest. Mammography shows an irregular density with coarse calcifications. Biopsy shows anucleate ghost adipocytes, lipid-laden macrophages, and foreign body giant cells surrounded by fibrosis. What is the diagnosis?

• A Lipid-rich carcinoma
• B Mammary duct ectasia
• C Granular cell tumor
• D Fat necrosis ✓

Explanation

Fat necrosis follows trauma or surgery and clinically mimics carcinoma as a firm, fixed mass that may calcify. Histology shows ghost outlines of necrotic adipocytes, foamy histiocytes, and foreign body giant cells with eventual fibrosis and dystrophic calcification. Duct ectasia instead shows periductal inflammation and inspissated secretions in dilated ducts, and it lacks the ghost adipocytes and giant cells seen here.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.