Objective: To examine the frequency of malignant growth in a nonfunctioning solitary thyroid nodule (SN) and in multinodular goiter (MNG).
Methods: We performed fine-needle aspiration biopsy (FNAB) of cold nodules in 154 patients. Eight patients with unsatisfactory FNAB specimens were excluded from the study. Of the remaining 146 patients, 95 (89 women and 6 men) had MNG. The other 51 patients (46 women and 5 men) had SN. The overall age range was 25 to 86 years (mean, 52).
Results: Of the 95 patients with MNG, 16 had abnormal cytologic findings and underwent surgical excision. Of these 16 patients, 12 had thyroid cancer (6 papillary, 3 follicular, and 3 Hürthle cell). Of the 51 patients with SN, 8 had suspicious cytologic findings, and 5 had surgical histologic evidence of thyroid cancer (3 papillary and 2 follicular). Four patients with papillary thyroid cancer (three from the MNG group and one from the SN group) had a history of exposure to neck irradiation. After exclusion of the patients with a history of neck irradiation, the rate of malignant involvement in cold nodules in the MNG group was 9.78%, in comparison with 8% in the group with SN (P = 0.89). Within the MNG group, 25% of the thyroid malignant lesions were of the Hürthle cell type.
Conclusion: Multinodularity of a goiter should no longer be considered an indicator of probable benign disease. In the assessment of all thyroid nodules, both SN and those in MNG, a thyroid scan can be helpful, and it should be followed by FNAB and cytopathologic examination of any nonfunctioning lesions. The incidence of malignant involvement in cold nodules of MNG does not differ significantly from that found in SN.