case_images: PMC7770628_01
case_images: Ultrasound showed a solid hypoechoic and irregularly shaped nodule 13 x 8 x 9 mm in size with microcalcifications, a taller-than-wide shape and suspicious extracapsular extension located in the upper pole of the right thyroid gland. (A) Transverse view; (B) longitudinal view; (C) Doppler blood flow signals; (D) elastography.
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case_images: PMC7770628_01_fendo-11-569308-g001.jpg
case_images: f1
case_images: To comprehensively evaluate the condition of IHP, cervical ultrasonography was performed and showed negative results for the parathyroid glands, but a solid hypoechoic mass measuring 13x8x9 mm with irregular margins, macrocalcifications, a taller than wide shape and suspicious extracapsular extension was accidentally found in the upper pole of the right thyroid gland ( Figure 1 ).
case_images: A suspicious parathyroid gland was found in the superior left area of the thyroid bed.
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case_images: f2
case_images: During the operation, only one suspicious parathyroid was found in the superior left position ( Figure 2 ), which was a small brown yellow nodule with a soft texture and approximately 3x2x2 mm in size that was supplied by the posterior branch of the superior thyroid artery; this gland was kept in situ.
case_images: TSH, hTg, and TgAb levels. The patient received RAI therapy 120 days after the operation.
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case_images: PMC7770628_01_fendo-11-569308-g003.jpg
case_images: f3
case_images: The patient was discharged 4 days after the treatment, and despite the long-term follow-up, the hTg value remained outside of the desired range recommended by the 2015th ATA guidelines ( Figure 3 ).
case_images: PTH and Ca levels.
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case_images: PMC7770628_01_fendo-11-569308-g004.jpg
case_images: f4
case_images: During the follow-up period, the serum calcium and PTH values were continuously monitored, and the variation curve is shown in  Figure 4 .