Endocrine Abstracts

A 13-year-old girl was noted to have a right-sided thyroid swelling on being reviewed by her paediatric endocrinologist. Neck examination confirmed a nodular mass in the right thyroid lobe, rubbery in nature, non-tender, mobile on swallowing but not on extrusion of the tongue. There was no thyroid bruit. She was clinically euthyroid with no dysthyroid eye disease or peripheral stigmata of thyroid dysfunction. Thyroid Ultrasound reported a grossly enlarged right thyroid lobe due to an in-homogeneous, solid, ill-defined, multi-loculated nodule approximately 3 × 5 cm. Thyroid Scintigraphy confirmed a large cold nodule in the same location. She underwent Total Thyroidectomy and Radioactive Iodine (I-131) Ablation Therapy (RAIT) 80-mCi in October 2006 with further RAIT 120-mCi in November 2007. Histology reported papillary carcinoma (incompletely excised) in the Right thyroid lobe and Micropapillary carcinoma (completely excised) in the left thyroid lobe on a background of Hashimoto’s Thyroiditis. Additionally, parathyroid parenchyma was noted in the periphery of the left lobe and two nodules of thymic tissue were attached to the right lobe. Radioactive iodine uptake (RAIU) scans post-ablation showed no uptake. Treatment with Levothyroxine 100 micrograms daily was commenced post-operatively. Calcium levels remained stable. Thyroglobulin remained suppressed for 14 years post-operatively until a rising level of 1.1 mg/ml was noted in October 2021. Anti-Thyroglobulin antibody levels were persistently negative. Thyroid Ultrasound revealed a few suspicious lymph nodes on the right side of the neck, largest measuring 1.1 cm × 0.8 cm. A similar abnormal node in the midline of the neck above the previous thyroid isthmus measured 0.9 cm × 0.6 cm. Fine needle aspiration (FNA) of this lymph node revealed metastatic papillary thyroid carcinoma. Surgical consultation advised against surgical intervention, and a 3^rd dose of RAIT 120-mCi was administered in February 2022. RAIU scan post-ablation showed no uptake. A stimulated serum thyroglobulin level was taken and found to be 38.5 ng/ml indicating the possibility of Iodine refractory disease requiring surgical intervention. Thyroid Ultrasound post-RAIT revealed stable findings. Multi-disciplinary team (MDT) discussion advised surgical intervention via Central neck and Right neck dissection. Right extended selective neck dissection (II-IV, VI, VII) was performed in January 2023. Histology confirmed metastatic papillary thyroid carcinoma was present in 9 lymph nodes (9/20). The largest metastatic tumour deposit was present in one central neck lymph node, measuring 7 mm in diameter and showing extra nodal extension- P1nb. Post-operative follow-up imaging showed no disease recurrence. Intended TSH suppression (below 0.1 micIU/ml) is being achieved.