Oral Manifestation of Cowden Syndrome, a PTEN Hamartoma Tumour Syndrome: A Case Report

Introduction
PTEN Hamartoma Tumour Syndrome (PHTS) is a group of clinical disorders, which includes Cowden Syndrome. Cowden Syndrome is a rare autosomal dominant condition caused by alterations in the PTEN gene. It is characterised by multiple hamartomas and an increased risk of developing benign and malignant tumours of the breast, thyroid and kidney. Oral manifestations include fibroepithelial polyps, fibromas and papillomas which commonly occur in 80-90% of patients. A clinical diagnosis is usually made which can be confirmed by genetic testing if necessary.

Case Report
A 65-year-old female was referred to the Oral Surgery Department of Dublin Dental University Hospital by her General Medical Practitioner regarding a raised nodule on the right lateral border of her tongue. Her medical history was significant for breast, thyroid and ovarian cysts. She never smoked cigarettes and did not consume alcohol.
Extra oral examination revealed no lymphadenopathy. Intraorally, there was lobulation of both the dorsum of the tongue and anterior hard palate, widespread gingival hyperplasia and multiple soft tissue growths on the right buccal mucosa and lateral border of the tongue. Excisional biopsies of these areas confirmed histology consistent with fibro-epithelial polyps.
Given the oral manifestations and unusual medical history, a referral to Clinical Genetics was made and a diagnosis of Cowden Syndrome was confirmed.

Conclusion
Cowden Syndrome is a rare PTEN hamartoma tumour syndrome. Patients affected can present with a variety of clinical symptoms often making it a diagnostic challenge for clinicians. Benign nodules in the oral cavity are one of the common signs of this syndrome. This case highlights the importance of a multidisciplinary approach, including genetic testing, to support diagnosis and clinical management of patients.