Retrospective cytological evaluation of indeterminate thyroid nodules according to the British Thyroid Association 2014 classification and comparison of clinical evaluation and outcomes

Abstract

Abstract:The cytology of 130 indeterminate nodules (Thy 3) was retrospectively reviewed according to the British Thyroid Association 2014 classification. Nodules were divided into Thy 3a (atypical features) and Thy 3f (follicular lesion) categories. Histology was available as a reference for 97 nodules. Pre-surgical evaluations comprised biochemical tests, color-Doppler ultrasonography (US), semi-quantitative elastography-US (USE), contrast-enhanced US (CEUS), and mutation analysis from cytological slides. Thyroid malignancy was the final diagnosis for 19% of surgicallytreated nodules. No statistically significant difference in the risk of malignancy was found between Thy 3a (26%) and Thy 3f (14%) nodules. Histology of the Thy 3a and Thy 3f nodules showed a higher incidence of Hurtle cell adenomas in Thy 3f (29%) than in Thy 3a (3%) nodules (P=0.01). The only pre-surgical difference concerned the BRAF V600E mutation, which was positive in some Thy 3a but not in any Thy 3f nodules (P=0.04). Receiver-operating characteristic (ROC) analysis was used to obtain cut-off values from US (score), USE (ELX 2/1 strain index), and CEUS (time-topeak index and peak index) data. The cut-off values were similar for Thy 3a and Thy 3f nodules. Data showed that malignancy can be suspected if the US score is >2, ELX 1/2 strain index >1, time-to-peak index >1, and peak index <1. In a sub-group of 24 revised nodules (12 Thy 3a and 12 Thy 3f) with histology as a reference, the diagnostic power of cumulative pre-surgical analysis by means of US, USE, and CEUS showed high positive and negative predictive values (83% and 100%, respectively) for the presence of malignancy in Thy 3a and Thy 3f nodules. In conclusion, in our series of revised Thy 3 nodules, malignancy was low and displayed no significant differences between Thy 3a and Thy 3f categories. The use of cut-offs based on histology as a reference could reduce surgery. Our data support the conviction that, in mutation-negative Thy 3a and Thy 3f nodules, observation should be the first choice when not all instrumental results are suspect.

Molecular Variants and Their Risks for Malignancy in Cytologically Indeterminate Thyroid Nodules

“…Reported Variants and Fusions 98.1%(16,18,20,22,24,25,28,(30)(31)(32)46,(49)(50)(51)(52)(53)55,56,59,61,62,64, …”

Role of Strain Elastography and Shear-Wave Elastography in a Multiparametric Clinical Approach to Indeterminate Cytology Thyroid Nodules

“…Elastosonographic and CEUS examinations were performed as previously reported [ 3 ] at the Interventional Radiology Unit and validated by the same radiologist with more than 5 years of experience in elastosonography. Conventional US and USE were performed by means of a hand-held GE Logiq E9 US scanner (GE Medical, Milwaukee, IL, USA) equipped with ML 6–15 linear probe working in the range of 6–15 MHz.…”

“…The clinical management of thyroid nodules with indeterminate cytology is still controversial [ 1 , 2 ]. Despite continuous updating of cytological classifications in order to improve the risk stratification of these lesions, a significant number of nodules still do not reach a cytological definition [ 3 – 8 ]. In such cases, physicians have to adopt a clinical approach that can balance the risk of malignancy and the need to avoid useless surgery.…”

“…In such cases, physicians have to adopt a clinical approach that can balance the risk of malignancy and the need to avoid useless surgery. Several ancillary techniques are now available to support this choice; molecular tests for genetic mutations have shown considerable specificity and positive predictive value in detecting malignancies [ 3 , 9 – 11 ], and the use of combined tests has been seen to enhance their negative predictive value [ 11 ]. However, the routine use of complete genetic profiling may not be feasible [ 9 ].…”

“…Moreover, the use of nuclear medicine techniques, such as 18 FDG-PET, adds no further information in such cases [ 12 ]. Conventional ultrasound (US) has proved helpful in the management of these lesions, and several scoring systems with satisfactory accuracy and predictive value are now available [ 3 , 6 , 13 – 18 ]. While few data are available on the role of contrast-enhanced ultrasound (CEUS) in indeterminate-cytology nodules [ 19 ], its utility in distinguishing benign from malignant thyroid lesions and in the evaluation of cervical lymph nodes has already been proved [ 20 – 22 ].…”