Granulomatous mastitis following stereotactic core-needle biopsy: A case report.

Idiopathic granulomatous mastitis is a rare, chronic inflammatory disease of the breast of uncertain etiology that can mimic breast cancer. In rare instances, it may emerge secondary to trauma to the breast. We present a case of a 66-year-old woman who initially underwent a benign stereotactic core-needle biopsy of her left breast complicated by a small hematoma which initially remained unchanged mammographically and sonographically for 1 year; then, it enlarged unexpectedly at the 21-month interval follow-up prompting an ultrasound-guided biopsy revealing granulomatous mastitis.