Incidence, malignancy rates of diagnoses and cyto-histological correlations in the new Italian Reporting System for Thyroid Cytology: An institutional experience.

ABSTRACT

OBJECTIVE: FNA biopsy is considered as the most accurate method for the selection of patients with thyroid nodules that need for surgery or for the wait and see management. The aim of the present study is to clarify the risk of malignancy for the cytological data classified according to the 2014 Italian reporting system. METHODS: We report a retrospective analysis of 4043 patients in our institution's experience during the period April 2014 through December 2016 with the Italian reporting system for thyroid cytology. RESULTS: The diagnostic incidences of the 4043 cases were as follows 9.8% TIR1; 1.3% TIR1C; 70% TIR2; 6.6% TIR3A; 4.5% TIR3B; 2.4% TIR4; 5.2% TIR5. A repeated aspiration was carried out in 68 out of 269 cases (25%) classified as TIR3A. A total of 407 cases with cytology underwent surgical resection. A malignant neoplasm was detected in 261 out of 407 (64%) cases. Regarding TIR3B, surgical excision was undertaken in 109 cases, which included 42 high-risk lesions and 67 Hürthle cell neoplasms. The risk of malignancy was significantly higher in the former compared to the latter (50% vs 9%; P<.05). CONCLUSIONS: This investigation emphasises the reliability of the 2014 Italian Reporting System concerning the mutual frequency of the diagnostic categories. The risk of malignancy is perfectly within the range of the estimated values.