Preoperative serum thyroglobulin concentration is an independent predictive factor of malignancy in follicular neoplasms of the thyroid gland

BACKGROUND: A distinction between a benign follicular neoplasm (FN) and a malignant FN based entirely on cytologic examination of fine-needle aspiration biopsy is not possible. The aim of this retrospective study was to find predictive factors of carcinoma in patients with FN. METHODS: A chart review of 388 patients (314 females, 74 males; mean age 50 years, range 9-81 years) with FN, who were surgically treated between 1988 and 2009, was performed. Predictive factors for malignancy were identified by the chi-squared test and multivariate logistic regression. RESULTS: The histopathological diagnoses were carcinoma, adenoma, and benign goiter in 127 (33%), 126 (32%), and 135 (35%) patients, respectively. The independent predictors of malignancy as shown by multivariate logistic regression were age of patients (OR 1.88, P = 0.008), solitary tumor (OR 1.72, P = 0.037), and Tg concentration (OR 2.36, P = 0.001). Carcinoma was more common in patients younger than 45 years, with solitary tumor and with preoperative serum Tg concentration more than 400 ng/ml. CONCLUSIONS: The independent predictors of malignancy in FN were age of patients, solitary tumor, and preoperative Tg concentration. The determination of Tg concentration may be useful in the patients with FN in order to decrease the number of completion thyroidectomies.