Objectives: The recent American Thyroid Association management guidelines suggest cervical ultrasonography (US) surveillance in patients with differentiated thyroid cancer (DTC). This study was conducted to identify predictive factors that can determine whether subsequent fine needle aspiration guided by ultrasound (US-FNA) is indicated in patients with lesions detected by US after surgery for DTC.
Design: Retrospective analysis at a university-based tertiary hospital.
Patients and measurements: We reviewed 207 cases of postoperative US-FNA in 180 patients diagnosed with DTC. We examined the relationship between US-FNA histology and clinical factors, imaging abnormalities found by US and with other modalities and pathological staging.
Results: US-FNA recurrence was positive in 56 (27%) cases and negative in 151 (73%) cases. The mean lesion size for FNA was 0·83 cm (range 0·2-2·9 cm). Univariate analysis indicated that tumour recurrence on US-FNA is associated with elevated stimulated thyroglobulin (sTg) levels, with the initial size of the primary tumour, with abnormal US findings, including the ipsilateral site, level III or IV location and extrathyroidal extension, and with other imaging abnormalities. However, multivariate analysis revealed an independent association between recurrence on FNA and suspicious US findings (OR 9·410; 95% CI 3·322-26·654; P<0·001) and elevated serum sTg (OR 5·001; 95% CI 1·067-23·485; P =0·041). Findings on US that were discriminating for recurrent nodules at the thyroidectomy site were abnormalities that were not oval shape or which had an irregular margin. Calcifications or cystic change showed a low sensitivity of 14%.
Conclusions: US-FNA for diagnosis of recurrence after surgery for DTC may be limited to patients with elevated sTg or with lesions that have specific suspicious US findings.
© 2011 Blackwell Publishing Ltd.