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Hypofunctioning thyroid nodules in patients with hyperthyroidism may be thyroid carcinomas

(July 2002)

The background of the study. Some patients with hyperthyroidism caused by Graves' disease also have a thyroid nodule. This study was done to determine the clinical characteristics and pathologic findings in patients with Graves' hyperthyroidism who had hypofunctioning ("cold") thyroid nodules.

How the study was done. The records of all patients with hyperthyroidism caused by Graves' disease seen at a single center from 1990 to the present were reviewed. Patients were excluded if nodule function was not assessed or treatment was not described. The records of the remaining patients were reviewed to obtain demographic data; findings on physical examination; results of thyroid radioiodine scans and other tests, including pathology; and treatment. The results in patients with scan defects were compared with the results in patients who had no scan defects.

The results of the study. There were 325 patients, of whom 39 (12 percent) had a cold nodule. Subsequent evaluation revealed no nodule in 11 of these 39 patients (28 percent). Six patients (15 percent) had a fine-needle aspiration biopsy that revealed benign thyroid follicular cells. None of these patients had enlargement of their nodule during follow-up (8 to 264 months). The remaining 22 patients underwent surgery, which revealed papillary carcinoma in 6 patients (15 percent of the patients with cold nodules), a benign nodule in 14 patients, and no nodule in 2 patients.

There were no differences in age, numbers of women and men, duration of hyperthyroidism, goiter size, or 24-hour thyroid radioiodine uptake values in the patients with cold defects and the control patients. Sixteen of the patients with cold defects, including two of the six patients with a carcinoma, but none of the control patients, had a palpable nodule.

The conclusions of the study. In patients with Graves' hyperthyroidism, thyroid radioiodine scanning may reveal cold thyroid nodules, some of which are thyroid carcinomas.

The original article. Stocker DJ, Foster SS, Solomon BL, Shriver CD, Burch HB. Thyroid cancer yield in patients with Graves' disease selected for surgery on the basis of cold scintiscan defects. Thyroid 2002;12:305-11.