ESPE Abstracts

Introduction: The phosphatase and tensin homolog (PTEN) hamartoma tumour syndrome (PHTS) groups related multi-system genetic disorders linked to germline mutations in the PTEN gene. There is an increased risk of thyroid cancer in PHTS, with some cases arising in childhood. Annual surveillance for thyroid cancer by ultrasound is recommended.

Case report: A 15 year old female was referred to Paediatric Endocrinology by Clinical Genetics for thyroid surveillance given a 10q23.31 deletion involving the PTEN gene. She had significant developmental delay, with severe learning difficulties, a diagnosis of autism spectrum disorder (ASD) and seizures. Her father and brother were known to have the same PTEN deletion. Both parents had head circumferences above the 97th centile. Her father had undergone a total thyroidectomy for a large multinodular goitre. He also had a history of lipomas and a cerebral vascular malformation. Our patient was clinically euthyroid and had a normal thyroid examination. Her head circumference plotted on the 50th centile. She did not have any mucocutaneous lesions, lipomas or haemangiomas. Thyroid function was normal (TSH 0.68 mu/l (0.34 – 5.6), FT4 14.8 pmol/l (7.5 – 21.1)). A thyroid ultrasound scan revealed bilateral thyroid lesions predominantly cystic in nature, without microcalcification or cervical lymphadenopathy. The patient required a general anaesthetic for fine needle aspiration (FNA), which was performed on the largest lesion (15 mm diameter). Histology was inconclusive and reported mostly colloid. Annual ultrasound surveillance with likely FNAs versus definitive surgery was discussed at the oncology thyroid MDT. Following an in depth discussion with the family, the patient, who was not Gillick competent, underwent a prophylactic total thyroidectomy aged 16 years. She was commenced on lifelong levothyroxine. Histology reported multinodular hyperplasia.

Discussion: Learning points from the management of this individual are as follows. There is an estimated 35% lifetime risk of thyroid cancer in PHTS. Annual surveillance is therefore essential, however ultrasound findings in this clinical context may warrant an immediate FNA. Yet such a procedure may not be easily tolerated in these individuals, repeat FNAs may be required over time and whilst FNA can be diagnostic, accuracy in children varies. Therefore, the risks versus benefits of repeated general anaesthetic in order to perform an FNA, should sedation fail, need to be considered. Another consideration is the inevitable progression of multinodular hyperplasia making thyroid surgery more challenging with time. We therefore advocate an individualised approach to mitigating thyroid cancer risk in children with PHTS.