The impact of repeat FNA in non-diagnostic and indeterminate thyroid nodules: A 5-year single-centre experience

FNA is a well-established method for the preoperative diagnosis of thyroid nodules, but limitations still reside among non-diagnostic and indeterminate samples. The objective of the present study was to assess the impact of repeat FNA in thyroid nodules primarily classified as non-diagnostic and indeterminate, with the evaluation of the diagnostic resolution rate after the reassessment of the nodule.

We retrospectively collected all cases of thyroid FNA at our institution in the last 5 years that had one or more repeat aspirations of the same nodule, calculating the percentage of samples with change in the diagnostic category. Additional collected data included sex, age and interval between the repeat aspirations.

One hundred and seventy-eight specimens from 167 patients (140 female, 27 male) with a median age of 56 years (range 11-90) were included in the study. Among the 86 cases primarily classified as non-diagnostic, 25 (29.1%) remained in the same category after the first reassessment and only 18 (20.9%) after the second repeat aspiration. Among the 40 indeterminate cases, only 10 (25%) retained their status after the second aspiration, with no change after the third assessment.

Repeat aspiration of non-diagnostic and indeterminate thyroid nodules had a positive impact in both groups, with diagnostic resolution rates of 80% and 75%, respectively. The present study therefore endorses the use of such strategy for the initial follow-up of nodules with no definite diagnosis, especially in low-resource centres with limited access to modern molecular technologies.