BACKGROUND: Cholesterol granuloma is a benign condition that can occur in the breast following trauma, breast biopsy, or surgical procedures. Cholesterol granuloma can mimic breast cancer on imaging studies. This report is of a case of an enlarging breast mass due to a repeat needle biopsy in the vicinity of a previous biopsy that resulted in a cholesterol granuloma that appeared to increase in size on ultrasound imaging. The mammographic and high-resolution sonographic imaging features of cholesterol granuloma of the breast are described, with a review of the literature of published cases of cholesterol granuloma of the breast diagnosed on imaging.

CASE REPORT: A 52-year-old woman had undergone multiple rounds of breast ultrasound scans for multiple breast nodules. At six-month follow-up with a needle biopsy was performed that showed benign cystic change. At 18-months follow-up high-resolution sonographic imaging showed a circumscribed, oval, hypoechoic mass with a benign morphology in the vicinity of the biopsy site. The size of the hypoechoic nodule increased progressively, and histopathology confirmed the diagnosis of a benign cholesterol granuloma.

CONCLUSIONS: This case demonstrated that cholesterol granuloma of the breast can increase in size after repeats adjacent breast biopsy, and may retain benign morphological features on ultrasound imaging, despite increasing in size.

Keywords: Biopsy, Breast, Mammography, Ultrasonography, Cholesterol Granuloma, Biopsy, Needle, Breast Diseases, Cholesterol, Granuloma, Foreign-Body, Ultrasonography, Mammary