Thyroid nodules with Hurthle cells: the malignancy risk in relation to the FNA outcome category

摘要

PurposeThe aim was to find whether the presence of Hurthle cells (HC) in a smear influences the categorization of FNA results or the risk of malignancy (RoM) of particular categories of cytological diagnosis.Methods25,220 FNA performed in a single center in years 2005-2017 were analyzed. Almost all the examined patients were exposed to moderate iodine deficiency for most of their lives. The distribution of FNA outcome categories was compared between two groups: with or without HC (HC and non-HC). The RoM was evaluated on the basis of postoperative histopathological examination (3082 patients).ResultsHC were found in 7.5 of diagnostic FNA. HC nodules were classified into categories II (78.2 vs. 91.9, p<0.0000) and VI (0.4 vs. 1.2, p=0.0017) less often than non-HC nodules, but more frequently to categories III (14.4 vs. 5.8, p<0.0000), IV (11.2 vs. 0.9, p<0.0000) and V (1.5 vs. 0.8, p=0.0013). There were no significant differences in RoM between HC and non-HC nodules. The RoM in HC and non-HC nodules of particular categories of the Bethesda system was as follows: II: 1.8 vs. 0.8, III: 9.7 vs. 3.8 when only the last FNA was considered and 10.8 vs. 6.4 when the category III in any performed FNA was considered; IV: 12.7 vs. 10.9; V: 41.7 vs. 58.2; and VI: 100 vs. 96.9.ConclusionsHC nodules are classified into categories of equivocal cytological outcomes more often than nodules without HC. Nevertheless, the presence of HC in a smear does not significantly affect the RoM of FNA categories.