Thyroid nodules that disappear—a case report on pseudonodules in thyroiditis

Background: Patients with thyroid nodules commonly present to clinical attention. The usual evaluation includes a through history and physical examination, laryngoscopy, ultrasonography, and a fine-needle aspiration cytology (FNAC) when there is a suspicion of malignancy. This case report highlights the entity of pseudo-nodules that can resolve spontaneously with conservative management. Case Description: A 58-year-old Chinese female in Singapore presented with an episode of left anterior neck pain and swelling that started spontaneously and lasted a month. Thyroid function tests showed subclinical hyperthyroidism without antibodies against thyroglobulin, thyroid peroxidase, and thyrotropin receptor. Ultrasonography of the neck showed two right-sided thyroid nodules (2.5 and 1.1 cm) with intermediate risk of malignancy. Thyroid scintigraphy revealed overall reduced tracer uptake with photopenia of the right mid-to-lower pole. She was diagnosed with subacute thyroiditis and managed conservatively with non-steroidal anti-inflammatory drugs (NSAIDs). During subsequent reviews, her thyroid nodules nearly completely resolved 9 months later and her thyroid function normalized. Conclusions: Our patient's clinical course, imaging, and laboratory work-up supports a diagnosis of De Quervain's thyroiditis. Inflammatory pseudonodules can be found in this condition and are known to resolve spontaneously. Except for marked hypoechogenicity, the pseudonodules do not display other suspicious features on ultrasonography. As thyroid nodules are increasingly diagnosed, it is timely to remember the entity of inflammatory pseudonodules which can spontaneously resolve. Clinicians should recognize this diagnosis to avoid performing unnecessary FNAC or generating excessive concerns about cancer in their patients.