The 2014 Italian Reporting System for Thyroid Cytology: Comparison with the National Reporting Systems and Future Directions

The main purpose of the management of patients with thyroid nodules is the distinction of those who are candidate to surgery in respect to those who can simply be clinically followed. This decision primarily relies on the morphologic classification of cytologic samples obtained by fine-needle aspiration, complemented by clinical and imaging findings and, in selected cases, by molecular analysis. Various 4to 6-tiered reporting schemes for thyroid cytology have been proposed and their validity has been demonstrated in several studies. The most controversial points concern the definition of the “indeterminate” cytology and the consequent nonnegligible rate of unnecessary diagnostic surgery. An update of the 2007 Italian Consensus Statement for the reporting and classification of thyroid nodule cytology was planned during the period of 2011-2014 and it has been devised by a Committee composed of five pathologists and five endocrinologists, representing the National Societies of Pathology and Endocrinology. The 2014 Italian Reporting System for Thyroid Cytology, on the previous 5-tiered reporting scheme, includes a sub-classification of the “non diagnostic” diagnoses introducing the category TIR 1C for cystic lesions and the separation of the “indeterminate” category (TIR 3) into two subclasses (TIR 3A and TIR 3B) with expected different risks of malignancy and different managements. A definition of the cytologic criteria of inclusion in the different categories and a prospective multicenter trial are also planned to validate the effectiveness of the system.