Advance in evaluating the thyroid tumor

Abstract

Most thyroid tumors have been found incidentally by the doctor. Palpation of the neck is important for detection of the thyroid mass lesion. The hard tumor with irregular surface and poor mobility suggests malignancy. Ultrasonagraphic study helps to detect non-palpable small lesions and also to differentiate malignancy. Fine-needle aspiration (FNA) has been the most valuable test in helping to differentiate cancerous from benign conditions. We compared the preoperative cytologic results with the postoperative histologic results in 502 thyroid nodules from patients who underwent surgery at Tenri Hospital. Sensitivity and specificity for the malignant tumor was 77.7% and 97.4 respectively. 94% of the class four or five nodules proved to be malignant and 90% of the class two nodules proved to be benign postoperatively. False-negative diagnosis occured mainly in cases of the calcified tumor or the cystic tumor where sufficient material was not obtained. False-positive diagnosis were obtained from cases with the atypical adenoma or the adenomatous goiter with papillary change. In the presense of large masses, especially with compressive signs and symptoms, the imaging study we currently find of most benefit is the magnetic resonance imaging (MRI).