Abstract
Background and Objectives: Thyroid nodules are a common disorder. The majority of thyroid nodules are defined as “cold” because they concentrate little or no iodine in scintiscan in comparison to the adjacent thyroid tissue.
Material and Methods: In this retrospective study, 800 patients with cold thyroid nodules were surveyed and the result of thyroid scans were collected from their charts and analyzed by appropriate statistical test. In this retrospective study the results of new approach to cold thyroid nodules by FNAB were compared to previous method of selection of patients for surgery and the sensitivity, accuracy and benefits of FNAB were determined.
Results: 674 (84.2%) of the cases were females and 126 (15.8%) were males. An over all female to male ratio of 5 to 1.
The frequency of malignancy among surgically excised cold nodules were 23.3%. The proportion of malignant nodules was more frequent in patients in the 4th decade and less frequent in patients younger than 20 years or older than 70 years.
The mean age of the patients was 36.9 years. Neck mass was the most common symptom and the most common site of the nodule was in the right lobe.
In order to evaluate the accuracy of FNA we compared the preoperative FNA findings with post operative pathologic results in 491 nodules from patients whom underwent surgery.
In 491 thyroid nodules in which both results (FNA and pathologic) were available, false negative results were 14.2% and false positive findings were 5.8%. By comparing FNA and pathologic diagnosis in our study, FNA examination showed sensitivity of 85.5% and a specificity of 94.2% and an accuracy of 90%.
Conclusion: Fine needle aspiration is simple tool for diagnosis of single cold nodules, with sensitivity. 85% and accuracy of 90% with minimal complications and in majority of cases, prevent a major surgery in patients which clinically surgery in indicated. Its minimal complications like pain and occasional entrance to trachea seem to be negligible.