Endocrine Abstracts

JOINT1525

background: Subacute thyroiditis (SAT) is a transient, post-viral inflammatory disorder of the thyroid gland characterized by transient thyrotoxicosis, neck pain, and eventual recovery of thyroid function. In some cases, hypothyroidism may develop due to glandular damage. The coexistence of SAT and Graves’ disease (GD) is extremely rare, with only a few cases reported in the literature.

Patient findings: We report a case of the simultaneous occurrence of SAT and GD with active orbitopathy in a 46-year-old woman. The patient presented with malaise, generalized weakness, nausea, vomiting, neck pain, and orbitopathy symptoms persisting for approximately one month. Physical examination revealed a heart rate of 100 beats per minute, a diffusely enlarged and tender thyroid gland, conjunctival redness, eyelid swelling, and mild exophthalmos. Laboratory findings included: Thyrotropin (TSH) <0.01 mlU/l, Free thyroxine (FT4) >64.4 pmol/l, Free triiodothyronine (FT3) >30.7 pmol//l, Thyroglobulin 1038.52 ng/mL, Thyiroglobulin antibody 1.1 IU/mL, Thyroperoxidase antibody 19.1 IU/mL, Thyroid-stimulating hormone receptor antibody 19.1 IU/mL, Thyroid-stimulating hormone receptor antibody >40 IU/l, Erythrocyte sedimentation rate 85 mm/h, C-reactive protein 11.9 mg/dl and Interleukin-6 82 pg/mL. Thyroid ultrasound showed an enlarged, heterogeneous gland with hypervascularity. Ophthalmological examination confirmed active Graves’ orbitopathy with a Clinical Activity Score (CAS) of 4–5/7 based on EUGOGO criteria. The patient was treated symptomatically with thyrosuppressive therapy and pulse corticosteroids for 12 weeks.

Conclusion: The simultaneous occurrence of SAT and GD, especially with active Graves’ orbitopathy, is exceedingly rare. In this case, SAT-induced autoimmune alterations may have triggered the development of GD in a predisposed individual. This case highlights the importance of considering overlapping thyroid pathologies in complex clinical presentations.