Metastatic tumours detected as cold nodules on the thyroid scan

Although metastasis to the thyroid is not uncommon, metastatic tumours in the thyroid, masquerading as a primary cancer, are infrequent and it is rare for a metastasis to be manifest as a clinically evident thyroid mass (Meissner, 1971; Ram, 1981; Mailander & Graves, 1985; Lester et al, 1986). There are few reports of metastases detected as “cold” nodules on thyroid scans (Ram, 1981; Mailander & Graves, 1985; Lester et al, 1986). During a 10-year period from 1977 to 1986, 66 thyroid malignancies were imaged with99Tcm-pertechnetate in our hospital. Three of them were metastases from carcinomas elsewhere, detected as cold nodules on the thyroid scan. These cases are now presented.