Background
The aim of this retrospective study was to find predictive factors of carcinoma in patients with follicular neoplasm. The specific aim was to discover whether preoperative serum thyroglobulin (Tg) concentration in patients with thyroid neoplasm can differentiate between those with thyroid carcinoma and those with benign disease.
Material and Method
A total of 327 patients (263 females, 64 males, median age: 51.5 years) with follicular neoplasm in whom carcinoma was only suspected and who were surgically treated at the authors' institute in 1988-2004 were included in the study. Patients who had distant and/or regional metastases were excluded. Risk factors for malignancy were identified by the chi-squared test and logistic regression.
Results
The histopathological diagnoses were carcinoma, benign goiter, and adenoma in 119 (36%), 104 (32%), and 104 (32%) patients, respectively. The independent predictors of malignancy as shown by multivariate logistic regression were tumor diameter and preoperative Tg concentration. Thyroid carcinoma was more common in the patients with follicular neoplasm and serum Tg concentration over 300 ng/ml than in those with lower Tg concentrations.
Conclusions
Predictors of malignancy were tumor diameter and preoperative Tg concentration.

Keywords: Thyroglobulin - blood, Risk Factors, Predictive Value of Tests, Child, Aged, 80 and over, Biopsy, Thyrotropin - blood, Thyroid Neoplasms - pathology, Adolescent, Adenocarcinoma, Follicular - pathology