The Rate of Tumour Growth Does Not Distinguish Between Malignant and Benign Thyroid Nodules

OBJECTIVE: To clarify whether or not the rate of tumour growth is a useful measure for distinguishing papillary thyroid cancer from benign nodules. DESIGN: Retrospective study. SETTING: Teaching hospital, Japan. SUBJECTS: Fourteen patients with 27 nodules (<20 mm) followed up for 20 months or more. INTERVENTIONS: High resolution ultrasonography (US). MAIN OUTCOME MEASURE: Growth rate. RESULTS: There were 15 papillary thyroid cancers and 12 benign nodules. The median tumour diameters at the first and the last US examination were 9.0 mm (range 6-19) and 9.0 mm (range 5-21) in papillary thyroid cancers followed up for 37 months (range 21-85), and 11.5 mm (range 4-19) and 11.5 mm (range 5-23) in benign nodules followed up for 38 months (range 20-84), respectively. CONCLUSION: The rate of growth of thyroid nodules as documented by ultrasound did not prove to be useful in distinguishing between malignancy and benign disease of small thyroid nodules (<20 mm).