Department of Nuclear Medicine, Imam Khomeini Hospital, Tabriz University of Medical Sciences, Tabriz, Iran
In 30 patient with single cold thyroid nodule and normal thyroid function tests, 99mTc-MIBI scan is performed. The nodules are divided to hot (10), Warm (12) and cold (8). FNA reported papillary Ca in 4, suspicious follicular neoplasm in 3 and 23 benign lesions. 7 patients were operated on and had final pathology reports (4 papillary Ca and 3 benign lesions). All the nodules with no MIBI uptake were benign in this study. Warm nodules were benign for the most part (Only 1 papillary Ca was reported). Hot nodules revealed 3 malignant neoplasm but 7 benign lesions were also observed. In this study 99mTc-MIBI did not show an acceptible specificity for diagnosis of malignant thyroid tumors. However lack of MIBI uptake (Cold nodule) or evidence of some activity in the nodules (Warm nodule) is mostly seen in benign lesions.