A Case of Cowden Syndrome with Bilateral Breast Cancer: Invasive Carcinoma of No Special Type and Pure Cribriform Carcinoma

Cowden syndrome is an uncommon, multi-system disease that increases the risk of breast cancer. The most common breast malignancy is ductal carcinoma including ductal carcinoma in situ or infiltrating ductal carcinoma. Rare types of breast cancer exist, such as infiltrating tubular carcinoma and lobular carcinoma. There has been rarely a reported case of this type of breast cancer in Cowden syndrome. In this report, a 34-year-old woman diagnosed with Cowden syndrome underwent simple mastectomy for invasive carcinoma of no special type (NST) in the left breast, and simple mastectomy for cribriform carcinoma in the contralateral breast. Herein, we describe a case of Cowden syndrome with bilateral breast cancer, invasive carcinoma of NST in one breast and cribriform carcinoma in the contralateral breast.