A 52-year-old woman who underwent lumpectomy and radiotherapy for breast cancer 2 years ago now has a firm 2 cm area at the surgical scar. Examination suggests skin tethering. Mammogram shows a dense spiculated density with coarse calcifications. Core biopsy shows necrotic fat, lipid-laden macrophages, and foreign body giant cells. What explains the mammographic appearance?

• A Recurrent invasive ductal carcinoma with desmoplastic reaction
• B Radiation-induced angiosarcoma arising in the treated field
• C Fat necrosis cannot produce spiculated densities, so the report is discordant
• D Fat necrosis with saponification and dystrophic calcification mimicking malignancy ✓

Explanation

Fat necrosis after surgery or radiotherapy undergoes saponification when damaged adipocytes release fatty acids that combine with calcium, producing dystrophic calcifications. The accompanying fibrosis can form spiculated densities and cause skin retraction, closely mimicking carcinoma on imaging. The core biopsy showing necrotic fat, foamy macrophages, and giant cells is diagnostic and excludes recurrence. Radiation angiosarcoma typically appears as bruise-like cutaneous plaques years later, not as a scar-area mass with coarse calcifications.

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.