Endocrine Abstracts

A 54-year-old female presented to the neurologist in December 2017 with neuromuscular right arm weakness, lethargy and fascial swelling. She had a normal MRI head before being referred to the endocrine clinic with a TSH >125 mIU/l (0.27–4.2 mIU/l). Free T4 was 0.3 pmol/l (12.0–22.0) with a free T3 of <0.4 pmol/l (3.1–6.8). The thyroglobulin antibody was 1366 IU/ml (0–115) with a normal thyroid peroxidase level (TPO) 29.7 (0–34). No previous thyroid disease or a preceding viral illness and no thyroid eye signs. A thyroid ultrasound scan showed features consistent with autoimmune thyroiditis. She was diagnosed with primary autoimmune hypothyroidism and treated with levothyroxine 100 mcg daily with resolution of her neuromuscular weakness. She was discharged in June 2016. She presented in June 2017 to the ophthalmologist with a 3-month history of periorbital oedema. She had a TSH< 0.01, free T3 10.03, free T4 36, TPO 13.25, TG Ab 3508 and a TSH receptor antibody >40 (0–0.8) IU/l indicative of Graves’ disease. Levothyroxine was stopped and a thyroid ultrasound scan showed the thyroid gland was markedly heterogeneous with a mildly increased doppler vascularity. A technetium scan showed increased uptake (1.7%) in the right thyroid lobe relative to the left (0.8%). The patient was clinically euthyroid with some mild periorbital oedema. Carbimazole 5 mg was commenced in view of the suppressed TSH and an MRI of the orbits showed diffuse enlargement of extraocular muscles with bilateral proptosis, compatible with thyroid ophthalmopathy. Her thyroid eye disease was refractory to IV methylprednisolone 4.5 g over a period of 12 weeks. She proceeded to radiotherapy with some initial response and may require orbital decompression. At present, she remains off Carbimazole and levothyroxine (TSH 4.14, free T3 3.3, free T4 10.6, TG Ab 913).