Fine needle aspiration in the management of benign thyroid cysts

Resolution of cystic thyroid lesions after aspiration occurs in 8-45% of cases, the remainder require treatment for residual tumour or recurrent cysts. The aim of this study was to identify patient characteristics that predict cyst recurrence to enable these patients to undergo early surgery.

A retrospective analysis of 123 patients with benign thyroid cysts that were suitable for conservative management was undertaken. Demographic, clinical, ultrasound and fine needle aspiration cytology data were collated for patients who underwent surgery or were managed conservatively. Univariate and multivariate analyses were performed to identify factors predictive of cyst recurrence.

Of the 123 patients, 43 underwent surgery consequent on cyst recurrence or persistent symptoms after aspiration, and 80 were treated by aspiration alone. There were 17 males and 106 females, of mean age 45.5 years. The mean cyst size was 27 mm. Those undergoing surgery had a significantly greater mean cyst size (P = 0.001). The only factor predicting cyst recurrence on univariate analysis was absence of follicular cells on initial aspiration (P = 0.005). Multivariate analysis confirmed absence of follicular cells as an independent characteristic predicting recurrence, the odds ratios for recurrence was 3.18 (95%CI 1.39-7.29).

The present study suggests consideration of early surgery for patients with thyroid cysts with absence of follicular cells on initial cytology.