Cytological classification of thyroid nodules. Proposal of the SIAPEC-IAP Italian Consensus Working Group

In 20062007, a committee was established by the Italian Societies of Endocrinology (SIE and AME) and Pathology (SIAPEC-IAP), composed of invited endocrinologists with special interest in thyroid diseases, endocrine pathologists and cytopathologists. The main objectives of the committee were to analyse current diagnostic practice and reporting of fine needle aspiration biopsy cytology, and to define a consensus on the definition of each individual diagnostic category. Such a definition should include a shared, brief description of the main cytomorphological features followed by categorisation of the diagnosis in a five-tiered system (TIR 1 through 5). The definition should also provide a summary of clinical implications for each cytological diagnosis. The committee met several times to analyse the currently proposed international classification schemes. Different diagnostic reporting approaches were discussed with clinical colleagues, and the suggested therapeutic attitudes were recorded. The following consensus document is the final proposal.