A Case of Cowden Syndrome Diagnosed with the Onset of Breast Cancer

Abstract

Cowden syndrome is caused by germline pathogenic variants in the PTEN gene, resulting in multiple hamartomatous lesions throughout the body, approximately 30% of which are associated with breast cancer. Here, we report a case of Cowden syndrome presenting with breast cancer. A 34-year-old woman was diagnosed with left breast cancer at a nearby clinic and was referred to our department. She had a family history of breast cancer, and her brother and his child had been diagnosed with Cowden syndrome PTEN genetic testing for her also revealed the same pathogenic variant. In addition, the patient met the diagnostic criteria because of her history of thyroid tumor resection, macrocephaly, esophageal glycogen acanthosis, multiple lipomas, and colon polyps, and Cowden syndrome was diagnosed. In order to detect Cowden syndrome, it is useful to measure the head circumference and ask about hat size, along with family and past medical histories. In addition, although the fertilized embryo was cryopreserved in this case, sufficient information provision and decision-making support are important for preserving fertility in cases of hereditary tumors.