Papillary thyroid carcinoma masked by subacute thyroiditis

Papillary thyroid carcinoma (PTC) is the most common thyroid malignancy, while subacute thyroiditis (SAT) is a self-limiting inflammatory disorder. Their coexistence presents a diagnostic challenge. We report the case of a 34-year-old woman with six weeks of fever and neck pain. She presented with tachycardia, a painful goiter, and a right thyroid nodule. Tests showed elevated ESR and thyroglobulin. Ultrasound revealed a solid subcapsular nodule, and scintigraphy showed absent uptake. Biopsy confirmed PTC. Total thyroidectomy was performed, revealing classic and follicular variant PTC without invasion. She received I-131 ablation therapy and remains recurrence-free on follow-up. This case underscores the need for thorough evaluation in SAT cases with nodules, as inflammation can mask malignancy.