Endocrine Abstracts

Aim: In patients with papillary thyroid carcinoma (PTC), the incidence of subacute thyroiditis (SAT) is thought to be more frequent than estimated. The incidence of thyroid cancer is between 2.3% and 21.1% in Graves’ Disease (GD).

Case: A 31-year-old female patient applied with complaints of amenorrhea and hair loss in the 10th postpartum month. There was no history of COVID-19 infection, but Biontech vaccine were administered two years ago. Her family history revealed GD in her sister. On physical examination, blood pressure was 120/1 mm/Hg, pulse rate was 83 beats/min. Laboratory values were TSH:<0.1 mU/l (0.55-4.78), freeT4:2.1 ng/dl (0.89-1.76), freeT3:11.1 ng/l (2.3-4.2), antithyroglobulin:2.7 IU/ml (<13), antithyroidperoxidase: 10235 U/ml (<60), thyroid stimulating immunglobulin: 6.34 IU/l (0.1-0.55), TSH receptor antibody: 3.63 IU/l (<1.5). The patient refused thyroid scintigraphy because of breastfeeding. She admitted with severe pain over the right thyroid lobe the next day. There was tenderness in the right thyroid area and the body temperature was 37.5°. Thyroid US revealed hypoechoic heterogeneous areas in the superior anterior and the inferior anterior regions of the right lobe, a 16x24x1 mm isoechoic nodule with areas of cystic degeneration in the superior region and a 22x38x1 mm conglomerated isoechoic nodule with areas of cystic degeneration in the inferior region of left lobe. In laboratory analysis, TSH:<0.1 mU/l, freeT4:2.1 ng/dl (0.89-1.76), freeT3:15.1 ng/l (2.3-4.2), sedimentation rate: 1 mm/hour(0-20), CRP:8.1 mg/l (0-5). Her pain regressed and CRP values returned to normal after one week with NSAID treatment. However, since thyrotoxicosis did not resolve (TSH:<0.1 mU/l (0.55-4.78), free T4:3.05nd/dl(0.89-1.76), free T3: 18.1 ng/l (2.3-4.2), methimazole treatment was started. On the control thyroid US, heterogeneous hypoechoic areas have resolved. The thyroid FNAB cytology result of the dominant nodule in the left lobe was suspecious for follicular neoplasia and hurtle cell type. The patient underwent bilateral total thyroidectomy, and an infiltrative follicular subtype PTC 0.1 cm in diameter was observed in the right lobe in addition to hyperplastic colloidal nodules in non-tumor thyroid tissue.

Conclusion: SAT can be seen rarely in patients with PTC. In the literature, there are cases diagnosed with GD after SAT, cases of SAT concurrent with GD, and cases of concurrent GD and SAT after COVID-19 infection. Considering that the incidence of combinations of these three diseases is very rare, our patient is the first case in the literature with all three diagnoses.