Subacute granulomatous thyroiditis - case 567
Clinical presentation: A 41-year-old woman was referred for evaluation of a hyperthyroidism. She was treated for Graves' disease 12 years ago. Recently, she noticed fatigue, palpitations and subfebrility. Asked if there was neck tenderness or pain, she answered no.
Palpation: The right lobe was tender on palpation.
Laboratory examination: TSH 0.01 mIU/L, FT4 27.4 pM/L, CRP 6.3 mg/L.
Ultrasonography: The thyroid was echonormal and had several discrete, hypoechoic lesions. Some of these areas had indistinctive borders but none of them presented with typical blurred margins. The echogenicity index was around 15%. The vascularity was decreased.
Cytological diagnosis: subacute, granulomatous de Quervain's thyroiditis.
Additional laboratory test. TSAB 1.5 U/L (normal value below 1.5).
Suggestion. Non-steroid antiinflammatory drug. Repeat ultrasound and laboratory examination in 6 weeks.
Subacute thyroiditis can show any presentation from a completely asymptomatic condition to a very diseased one with high fever and spontaneous severe neck pain. This patient was much closer to the former. Moreover, the patient's medical history, the previous attack of Graves' disease, did not facilitate diagnosis either.
Vascularity has great relevance in the differential diagnostic of hyperthyroid state. If it is decreased, active hormone-producing disease is very unlikely.