Incidence of malignancy in solitary thyroid nodules

This study aimed to investigate the prevalence and clinical significance of solitary thyroid nodules in patients who underwent thyroid surgery.

A retrospective review was performed of the case notes of all adult patients who underwent thyroid surgery from January 2003 to December 2009. All patients with solitary thyroid nodules identified by ultrasonography were included.

In total, 225 patients underwent thyroid surgery. The prevalence of solitary thyroid nodules was 27.1 per cent (61 out of 225 patients). Seventy-two per cent of patients were women and the mean age at presentation was 52 ± 16 years. In all, 75.4 per cent of solitary nodules had neoplastic pathology and the malignancy rate was 34.4 per cent. The sensitivity and specificity of fine needle aspiration cytology for neoplasm detection were 73.9 per cent and 80.0 per cent, respectively. There was no association between the various ultrasonography parameters and malignancy risk (p > 0.05).

Solitary thyroid nodules should be investigated thoroughly with a high index of suspicion because there is a high probability (34.0 per cent) of malignancy.