Possible explanation of appearance of Warthin's tumor on I-123 and Tc-99m-pertechnetate scans

A 71-year old man presented with a parotid mass and a thyroid nodule. An I-123 scan revealed a "cold" nodule in the thyroid and uptake of the radioactive iodine in the parotid mass. On a Tc-99m-pertechnetate salivary gland scan, the parotid mass was "hot" and did not wash out with sodium perchlorate. At surgery, he was found to have a Warthin's tumor of the parotid gland and an adenomatous goiter. The reasons for the scan appearance of the Warthin's tumor are discussed. Since Warthin's tumors are benign and uptake of radioactive iodine in the extrathyroidal deposits of thyroid carcinoma is rare with the thyroid gland in place, the uptake of iodine by a salivary gland mass probably indicates a benign process.