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 mon
ths 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 follow
ed up for 37 months (range 21-85), and 11.5 mm (range 4-19) and 11.5 mm (ra
nge 5-23) in benign nodules followed up for 38 :months (range 20-84), respe
Conclusion: The rate of growth of thyroid nodules as documented by ultrasou
nd did not prove to be useful in distinguishing between malignancy and beni
gn disease of small thyroid nodules (<20 mm).