| Attempts have been made to distinguish benign from malignant nodules by seeking a change in size in response to thyroxine, perhaps related to dependency on TSH for growth. The incidence of malignant disease in patients who demonstrate an apparent response to thyroid hormone suppression is not known, but it is well established that some carcinomas may respond to suppression by reducing in size (32). Conversely a lack of response to a trial of thyroid hormone suppression is not specific for malignancy, the incidence of cancer in non-responders being between 12 and 40% (33). |
