A 60-year-old lady, presented with tremulousness of hands for 1 month and palpitation with excessive sweating for 3 months. She had a history of weight loss for 6 months, and gradually enlarging neck swelling for 3 years. She was nervous, irritable, and emotionally labile. Her weight was 46 kg, BMI 17, afebrile, pulse rate: 110/min/regular, blood pressure: 140/56 mm of Hg. Her thyroid gland was symmetrically enlarged, firm in consistency, nodular/lobular surface and mildly tender without any bruit. Palms were warm and sweaty with fine tremor in hands. All reflexes were exaggerated. There were no occular manifestations.\nInitial thyroid function tests (TFT) revealed high T3: 3.80 ng/ml (0.80-2.10), T4: 12.40 ug/dl (5.10-12) with a low TSH: 0.20 mU/L (0.70-5). Her TSH receptor antibody (TSAb): 25 U/L (Normal [nl.] <1), anti TPO antibody: 374 IU/ml (nl. <35) and thyroglobulin antibody: 268 IU/ml (nl. <65) were all strongly positive. Complete hemogram and ESR-18 mm/h (nl.-1-25) were normal. Ultrasonogram of thyroid revealed an enlarged gland with hypoechoic parenchyma with fibrous septa.99mTc pertechnetate scan (Tc99m scan) revealed enlarged thyroid gland with diffusely increased uptake of radiocontrast: 17% (nl. 0.4-4%) with some patchy defects in both lower poles. Thyroid FNAC showed sheets of Hurthle cells with abdunce of lymphocytes and sheets of regular follicular cells, indicating HT. She was observed on beta blockers. Repeat TFT, 3 months later showed: T3: 4.20 ng/ml, T4: 14.40 ug/dl, TSH: 0.001 μU. Repeat 99mTc pertechnetate scan was done, which again revealed enlarged thyroid gland with diffusely increased uptake of radiocontrast: 21% (nl. 0.4-4%) with same patchy defects in both lower poles. Antithyroid medication carbimazole was started.
46 years old female, mother of 3 children diagnosed as having primary hypothyroidism on the basis of clinical symptoms of easy fatigability, weight gain and increase sleep and a serum TSH level of >75 uIU/ml, FT4: 0.25 ng/dl and strongly positive thyroid antibodies in December 2002. Thyroxine 50 mcg/day was started which she continued. After 2 years she presented to us with complain of weight loss. Her serum TSH level was 0.035 uIU/ml and a T4: 7.84 ng/dl so thyroxine was stopped. She came for follow up after 5 months with serum TSH: 0.010 uIU/ml off thyroxine. After another 6 months her serum TSH remained suppressed with a value of 0.018 uIU/ml and an FT4 of 1.18 ng/dl and she remained off thyroxine. After further 2 years her TSH was 0.837 uIU/ml, FT4 0.922 ng/dl and FT3 3.06. And after 1 year she presented with a TSH level of <0.005 uIU/ml, raised FT4 and positive thyroid microsomal antibodies (1: 1600). Techniteum 99 thyroid scan showed diffusely increased homogenous tracer uptake. Neomercazole was started at the dose of 5 mg/day which was gradually increased to 10 mg/day. She followed up after 4 months with TSH: 0.01 uIU/ml, T4: 5.84 ng/dl, T3: 1.99 ng/dl. Neomercazole was continued. Then she came for follow up after 1 year, at this time she was clinically euthyroid but biochemically hypothyroid with serum TSH: 14.89 uIU/ml, FT4:0.65 ng/dl. Neomercazole was stopped and advised to repeat TFT’s after 8 weeks. She came after 4 months with TSH: 3.98 uIU/ml, so no treatment was advised. After a period of 1 year she again came with complains of weight loss and palpitations. At this time her TSH: < 0.005 uIU/ml, FT4: 2.25 ng/dl. Neomercazole was restarted and Radioactive iodine 131 ablation planned.