Subacute thyroiditis (de Quervain) presenting as a painless "cold" nodule.

A 49-yr-old woman presented with a solid, painless, nontender nodule in the left thyroid lobe. Thyroid scintigraphy revealed a solitary "cold" area in the left lobe and a slightly decreased 24-hr radioactive iodine thyroid uptake (9%). Although there were no specific clinical or biochemical signs suggesting thyroiditis needle aspiration cytology showed the presence of a subacute thyroiditis. Approximately 1 mo later the entire thyroid gland was affected leading to a completely suppressed thyroid radioiodine uptake and elevated serum thyroid hormone concentrations. This case illustrates that in the early phase of the disease, subacute thyroiditis may present as a solitary, painless, "cold" nodule and should be considered in the differential diagnosis of such lesions.