Subacute Thyroiditis Presenting as a Painful Thyroid Nodule and Subclinical Hyperthyroidism: A Case Report

This case report details the evaluation and management of a 55-year-old woman who presented to our endocrinology clinic due to low TSH and thyroid nodules previously evaluated by her ENT. The patient originally presented with anterior neck pain and dysphagia. Ultrasonography demonstrated thyroid nodules with suspicious features, prompting a fine needle aspiration (FNA). A biopsy showed a follicular lesion/atypia of undetermined significance (Bethesda III). Due to concerns for malignancy, a right lobectomy was recommended. Thyroid function tests showed subclinical hyperthyroidism. She presented to our endocrinology clinic and was diagnosed with subacute thyroiditis based on signs of symptoms, radioactive iodine scanning, and biochemical studies (elevated ESR). Within approximately seven months, thyroid function tests and inflammatory markers returned to baseline, and symptoms and physical findings resolved. The case highlights the importance of understanding the similarities and differences between subacute thyroiditis and malignant pathologies in order to avoid misdiagnosis and unnecessary procedures.