A Case of Cowden Syndrome

Introduction:
Cowden syndrome is part of the PTEN Hamartoma Tumor Syndrome spectrum. It is characterized by the presence of multiple hamartomas on the skin and mucous membranes and an increased risk of developing cancers of the thyroid, breast, uterus, kidney, colon, rectum and skin. Most cases are caused by genetic changes in the phosphatase and tensin homolog (PTEN) gene, inherited in an autosomal dominant manner. It is rare with an estimated prevalence of 1 in 200,000 to 250,000.

Case Description:
A 36-year-old female presented to the Veteran Affairs Endocrinology clinic for follow up of thyroid cancer. She had undergone a total thyroidectomy 9 years prior due to a large goiter, with pathology revealing papillary thyroid cancer. She received radioactive iodine ablation afterwards. Thyroid ultrasound showed a heterogenous soft tissue density measuring 1.8 x 1.1 x 1.6 cm in the left thyroid bed. Fine needle biopsy of the mass confirmed recurrent papillary thyroid cancer.

Her medical history includes endometriosis with right ovary cyst for which she underwent total hysterectomy with bilateral salpingo-oophorectomy, benign colon polyps status post resection, gallbladder polyps status post cholecystectomy, bilateral breast masses (measuring 0.5 cm on the right and 0.8 cm on the left) and multiple skin lesions. Family history is significant for multiple benign skin lesions and colon polyps in her father and breast cancer and endometriosis in her paternal aunts. 

Due to her extensive personal and family history of tumors, a comprehensive hereditary cancer panel was sent out. Results came back positive for the PTEN gene, indicating a diagnosis of Cowden syndrome.

She was referred to oncology for cancer surveillance, dermatology for regular skin checks and surgery for prophylactic mastectomy. She does not plan to have children, and she was advised to notify her first-degree family to have genetic testing done.

Discussion:
Patients with Cowden syndrome may present to the Endocrinology clinic for management of non medullary thyroid cancer, multinodular goiter or Hashimoto’s thyroiditis and may be noted to have multiple skin and mucous membrane lesions. They may report a history of breast tumors, endometrial abnormalities and polyps as in this case. After diagnosis is confirmed by genetic testing, cancer surveillance is the major focus of medical management given the high risk of malignancy.