Intraoperative decision making in follicular lesions of the thyroid: Is tumor size important?

Background: Intraoperative decision making in treating follicular lesions o f the thyroid remains controversial because there are no reliable preoperat ive or intraoperative factors predictive of malignancy This study was under taken to determine whether lesion size is a reliable factor that can be use d to predict a final pathologic diagnosis of follicular carcinoma. Study Design: This was a retrospective, case-matched control study. One hun dred consecutive patients with follicular carcinoma were matched by gender, age, and date of operation with 100 patients with follicular adenomas. Sev enty-nine matched pairs had pure follicular lesions and 21 matched pairs ha d oxyphilic variants of follicular lesions. After confirming adequate match ing, lesion size was compared between groups. Results: Regardless of whether all follicular lesions were analyzed or whet her only pure follicular or oxyphilic variant lesions were compared, there was no significant difference in lesion size between the carcinoma and aden oma groups. The mean size of all follicular carcinomas was 31.5 +/- 1.7 mm and the mean size of all follicular adenomas was 30.8 +/- 1,5 mm (p = NS). When the proportions of the carcinoma and adenoma groups were indexed by fi ve different size intervals and compared, there was again no significant di fference in any category. Conclusions: On the basis of this case-matched control study, the size of a follicular lesion cannot be used to predict a final diagnosis of follicula r carcinoma and is of no value when making intraoperative decisions about t he extent of thyroid resection. (J Am Coil Surg 1999; 189:253-258. (C) 1999 by the American College of Surgeons).