Breast cancer from the excisional scar of a benign mass.

Breast cancer developing from a surgical scar is rare; this type of malignancy has been reported in only 12 cases to date. Herein, we report on a 52-year-old female who developed infiltrating ductal carcinoma in a surgical scar following excision of a benign mass. Two years previously, the patient underwent surgery and radiotherapy for invasive ductal carcinoma of the contralateral breast. The initial appearance of the scar was similar to fat necrosis; it was observed to be progressively shrinking on follow-up sonography. On the two year follow-up ultrasound, the appearance changed, an angular margin and vascularity at the periphery of the scar were noted. A biopsy and subsequent excision of the scar were performed; the diagnosis of infiltrating ductal carcinoma of the scar was confirmed.