2023 Volume 50 Issue 4 Pages 295-300
In Cowden syndrome, benign breast conditions such as ductal hyperplasia, intraductal papillomatosis, adenosis, and fibroadenomas as well as cancers can occur, which may be difficult to distinguish. This case was a 35-year-old Japanese woman who had a history of thyroid follicular carcinoma and uterine cancer. She had multiple breast lesions and had been followed up with ultrasonography for about 19 years. She noticed a new lump in her right breast on her own, and ultrasonography showed a new intracystic tumor among various lesions, which was diagnosed as suspected cancer using vacuum-assisted breast biopsy (VAB). Contrast-enhanced magnetic resonance imaging showed a lesion on the contralateral side that was also suspected to be malignant. Bilateral mastectomy, bilateral sentinel lymph node biopsy, and bilateral axillary dissection were performed. She received adjuvant chemotherapy and radiation therapy, and she is taking anastrozole. Multi-gene panel testing showed germline pathological variants of the PTEN gene.
