Case Report: The Cowden Syndrome
A 32-year-old woman presented to the outpatient breast clinic with a several-month history of multiple tender breast lumps. She had no notable personal or family medical history. The physical examination revealed clustered papular growths on the lips (Panel A), which she reported had been present since childhood. On breast examination, there were multiple smooth,firm, and mobile lumps in both breasts as well as a 2-cm, painless, indurated mass in the upper medial quadrant of the right breast. Mammography showed dense breasts with multiple cysts.

Magnetic resonance imaging confirmed a mass in the right breast (Panel B, black arrow) and multiple smaller lesions consistent with papillomas (red arrows). Biopsy results were consistent with estrogen receptor positive invasive ductal carcinoma that was negative for human epidermal growth factor receptor 2; multiple intraductal papillomas were also present. Since the

Cowden syndrome was suspected, genetic testing was performed and showed an inactivating mutation in the tumor-suppressor gene encoding phosphatase and tensin homologue (PTEN). The Cowden syndrome, an autosomal dominant PTEN hamartoma syndrome, is associated with an increased risk of breast, thyroid, endometrial, and other cancers. Oral mucosal papillomas are commonly associated skin lesions. The patient underwent modified radical mastectomy of the right breast and prophylactic mastectomy of the left breast. In addition to genetic counseling, cancer surveillance is an important focus of treatment for patients with the Cowden syndrome.