Background: Fine-needle aspiration cytology of thyroid is the initial screening test for thyroid nodules. The Bethesda system classifies thyroid nodules into six categories. Each category is linked to a malignancy risk and has a recommended clinical management. The aim of this study is to analyze the thyroid cytology smears classified as Bethesda 1 and the role of repeated FNA in providing additional diagnostic information.
Methods: A retrospective chart review was performed of patients who had a category I FNA result and underwent repeated FNA of the same thyroid nodule between 2006 and 2018 at Hadassah Medical center, Jerusalem Israel. Demographic data, sonographic features, TIRADS classification, results of initial FNA and repeated FNA, surgical details, and final pathology were collected.
Results: Out of 1200 patients, 180 (15%) were classified as Bethesda 1 (115 female, 65 male) with a median age of 56 years (range 18-80) were included in the study. Among the 180 cases primarily classified as non-diagnostic, 38 (26.3%) remained in the same category after the after the second repeat aspiration. Most of these 38 cases were mainly cystic or spongiform benign-appearing nodules, that not necessarily needed a biopsy in the first place, and the FNA was done due to reasons such as symptomatic or growing nodule.
Conclusion: Repeat aspiration of non-diagnostic and indeterminate thyroid nodules had a positive impact, with diagnostic resolution rates in over 70% of the cases. Our study therefore endorses the use of such strategy for the initial follow-up of nodules with no definite diagnosis.
However, in certain nodules, with classic benign features, follow-up should be considered.
