case_images: PMC6854234_01
case_images: The clinical course including the patient's symptoms, medication administered, data of thyroid function tests and thyroid antibodies. The dates of pembrolizumab administration are as follows: first administration, Aug 7, 2018; second, Aug 27, 2018; third, Sep 18, 2018; fourth, Oct 15, 2018; fifth, Nov 12, 2018. Abbreviations: FT3, free triiodothyronine; FT4, free thyroxine; KI, potassium iodide; MMI, methimazole; PSL, prednisolone; TgAb, thyroglobulin antibody; TPOAb, thyroid peroxidase antibody; TRAb, thyroid stimulating hormone receptor antibody; TSAb, thyroid-stimulating antibody; TSH, thyroid stimulating hormone.
case_images: CRIE2019-2314032.001.jpg
case_images: PMC6854234_01_CRIE2019-2314032.001.jpg
case_images: fig1
case_images: Laboratory data showed hyperthyroidism, that is, undetectable serum thyroid-stimulating hormone (TSH) (<0.021 microIU/mL; standard range [SR] = 0.541-4.261) associated with elevated levels of both free triiodothyronine (FT3) (8.98 pg/mL; SR = 2.39-4.06) and free thyroxine (FT4) (3.45 ng/dL; SR = 0.71-1.52), with no goiter, no cervical pain, and no thyroidal ophthalmopathy on examination (Figure 1).
case_images: Thyroid ultrasonography performed the day after iodine treatment. Upper: Left is the intrathyroidal blood flow signal of the right lobe, Right is that of the left lobe. Lower: Left is right superior thyroid artery flow velocity, Vmax is 50.1 cm/s, Right is left superior thyroid artery flow velocity, Vmax is 44.0 cm/s.
case_images: CRIE2019-2314032.002.jpg
case_images: PMC6854234_01_CRIE2019-2314032.002.jpg
case_images: fig2
case_images: Thyroid ultrasonography performed the day after iodine treatment showed an increase in the superior thyroid artery flow velocity (Right 50.1 cm/s, Left 44.0 cm/s; >=50 cm/s as a criterion for increase) and a mild increase in the intrathyroidal blood flow signal (Figure 2).