Endocrine Abstracts

Background: Subacute thyroiditis is an inflammatory condition, most likely of viral origin, which typically presents wit low anterior neck pain, fever and transient thyrotoxicosis. Ultrasonography (US) usually shows a diffuse thyroid enlargement with ill-defined hypoechoic areas.

Case: A 55-year old women was admitted in the emergency room, with 2 weeks of anterior neck pain, cervical compressive symptoms of dysphagia, fever and palpitations. On physical examination a firm 4 cm neck anterior mass was palpable. Thyroid US showed a highly suspicious thyroid nodule in the isthmus/left lobe with 38 mm, apparent extrathyroidal extension, microcalcifications, with absence of intranodular flow in Doppler. A fine needle aspiration (FNA) was performed, with a benign result (follicular cells without nuclear atypia and macrophages). Laboratory results: TSH 0.01 mMUI/l (0.4–4.0), Free T4 3.19 ng/dl (0.93–1.70), Free T3 7.2 (2.0–4.4), erythrocyte sedimentation rate 110 mm (< 20), C-reactive protein (CRP) 26.1 mg/dl (< 20), Thyroid peroxidase antibody (TPO) and TRAb were negative. The patient was hospitalized, there wasn’t other site of infection, and the Endocrinology department was contacted due to suspicion of Subacute Thyroiditis and discrepancy between US thyroid nodule description and FNA result. Thyroid scintigraphy wasn’t performed due to recent contrast exposure (Neck Computed tomography). The patient was treated with Prednisolone with normalization of thyroid function, fever and apparent involution of thyroid nodule, with resolution of cervical compressive symptoms. After 3 months, Thyroid US showed a massive reduction of the thyroid nodule, with 12 mm, without the worrying aspects of first US. Transient hypothyroidism was noted without the need for Levothyroxine replacement, due to absence of symptoms, with normalization of thyroid function after 8 weeks.

Discussion: We present a case with an atypical presentation of Subacute Thyroiditis with a high suspicious 38 mm solitary nodule, with apparent extrathyroidal extension, mimicking thyroid malignancy. The presence of thyrotoxicosis and the symptoms of neck pain and fever were very suggestive of this disease, and after Prednisolone treatment, the thyroid nodule markedly reduced.