A 40-year-old woman gives a history of a seatbelt injury to the right breast three months ago. She now has a firm, mildly tender 2 cm lump with overlying skin dimpling. Mammography shows pleomorphic microcalcifications. What is the most likely diagnosis?

• A Invasive ductal carcinoma
• B Fat necrosis ✓
• C Phyllodes tumour
• D Plasma cell mastitis

Explanation

Trauma followed by a firm lump with skin tethering and suspicious calcifications is the classic presentation of fat necrosis, which clinically and radiologically mimics carcinoma. The history of trauma is the discriminating feature. Definitive distinction requires core biopsy or excision biopsy showing lipid-laden macrophages, foreign body giant cells and calcified fat. Invasive ductal carcinoma would be the key differential, which is exactly why histology is mandatory rather than assuming benignity from the trauma history alone.

Reference: Sabiston Textbook of Surgery, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.