Acute suppurative thyroiditis with Graves disease - A very rare association

Abstract

Acute suppurative thyroiditis is an uncommon disorder caused by a bacterial infection, usually presenting with normal thyroid function. It is a serious condition that requires a prompt diagnosis and treatment with antibiotics and supportive measures. A 62 years-old female presented with a painful cervical induration and odynophagia a week after a fish bone had been removed from her pharynx. She was febrile, and tachycardic and, on physical examination, a painful thyroid mass was detected. High inflammatory parameters and thyrotoxicosis were confirmed: thyroid stimulating hormone (TSH) < 0.01 mIU/L (normal range [NR] 0.27-4.2); free thyroxine (FT4) 3.86 ng/dL (NR 0.9-1.7) and anti-TSH receptor antibodies (TRABs) 5.3 U/L (NR < 1.5). Thyroid scintigraphy showed a diffuse uptake of the thyroid parenchyma suggesting Graves disease. Cervical ultrasonography revealed an abscess of the left thyroid lobe of 36 × 36 mm and fine needle aspiration biopsy (FNAB) with partial drainage was performed. Staphylococcus aureus and Streptococcus viridans were isolated, and directed antibiotic therapy was started. Clinical improvement was observed as well as a decrease of inflammatory parameters and the patient was discharged after 9 days of hospitalization. Eighteen days after discharge, thiamazole was initiated due to persistent thyrotoxicosis. Complete resolution of the abscess was documented within 6 months and the patient became euthyroid under thiamazole one year after initial presentation. To our knowledge, this is the third case reporting an association between acute thyroiditis and Graves disease. Furthermore, this is the first case detailing the simultaneous diagnosis of acute suppurative thyroiditis caused by a foreign body and Graves disease.

Keywords: Graves disease; acute thyroiditis; suppurative thyroiditis; thyrotoxicosis.

Figure 1. The fish bone removed from hypopharynx measuring 4 cm.

Figure 2. Neck computed tomography scan showing a hypodense nodule of thyroid left lobule measuring 30 × 35 × 35 mm, with tracheal compression.

Figure 3. Thyroid scintigraphy with 99mTc-Pertecnetate showing a cold nodule of the left thyroid lobe (blue arrow) surrounded by diffuse uptake of the thyroid parenchyma.

Figure 4. First thyroid ultrasonography performed showing a nodular lesion at left thyroid lobe with a solid central component, well delimited, without hypervascularity measuring 36 × 36 mm.