Squamous cell carcinoma of the nipple following radiation therapy for ductal carcinoma in situ: a case report

INTRODUCTION Radiation-induced nonmelanoma skin cancer was first reported seven years after the discovery of X-rays, but has received relatively little consideration in the literature. Specifically, nonmelanoma skin cancer after conservative surgery and radiation for early stage breast cancer has not been well studied. We report the case of a woman who developed squamous cell carcinoma of the nipple nine years after conservative surgery and radiation for ductal carcinoma in situ of the ipsilateral breast. We also review the relevant literature available to date. CASE PRESENTATION A 66-year-old African-American woman presented to the hospital with a non-healing ulcer of the right nipple. Her past medical history was significant for right breast ductal carcinoma in situ for which she had undergone lumpectomy and whole breast radiation therapy nine years previously. Mammography and magnetic resonance imaging studies were negative for recurrent breast cancer. However, the latter demonstrated abnormal enhancement in the nipple-areolar region. An incisional biopsy of the lesion demonstrated invasive squamous cell carcinoma. Subsequently, the patient underwent wide excision of the nipple-areolar complex. Sentinel lymph-node biopsy was offered but our patient declined. She was considered to have local disease and hence no further treatment was recommended. CONCLUSION This case represents the first reported occurrence of squamous cell carcinoma of the nipple to follow conservative surgery and radiation for ductal carcinoma in situ of the ipsilateral breast. It is likely that radiation overexposure resulted in a radiation burn and subsequent radiodermatitis, placing it at risk for squamous cell carcinoma. A diagnosis of squamous cell carcinoma should be considered in a patient with a nipple lesion following radiation therapy for breast cancer.