INCIDENCE AND TYPES OF NON-PALPABLE THYROID-NODULES IN THYROIDS REMOVED FOR PALPABLE DISEASE

The purpose of this study was to determine the number, size and types of non-palpable and ultrasound undected thyroid nodules in thyroid gla nds removed for a single palpable nodule. Twenty patients undergoing p artial (hemi- and subtotal) thyroidectomy and 40 patients having a tot al thyroidectomy were analyzed. Patients had no more than one palpable nodule, no cervical adenopathy and no history of previous thyroid sur gery. An ultrasound was performed routinely within four months of surg ery. Forty-six nodules were detected by final pathology in the partial thyroidectomy group but only 42% were detected by palpation and 59% b y ultrasound. The median diameter of non-palpable and ultrasound undet ected partial thyroidectomy nodules was 0.5 cm and all were benign exc ept for one case of lymphoma. Pathology detected 186 nodules in the to tal thyroidectomy group although palpation only detected 22% of these and ultrasound 42%. The median diameters of the benign and malignant n on-palpable nodules were 0.4 cm and 0.25 cm respectively. Most of the undetected nodules in the total thyroidectomy group were benign, but t here were 20 non-palpable and 18 ultrasound undetected papillary carci nomas.