Comparison of 5-tiered and 6-tiered diagnostic systems for the reporting of thyroid cytopathology

Massimo Bongiovanni, Stefano Crippa, Zubair Baloch, Simonetta Piana, Alessandra Spitale, Fabio Pagni, Luca Mazzucchelli, Camillo Di Bella, William Faquin

Research output: Contribution to journalArticle


BACKGROUND: At present, thyroid fine-needle aspiration (FNA) specimens are diagnosed using a tiered classification scheme, with the most popular of these being the 5-tiered and 6-tiered systems. In this study, the authors present their institutional experiences using these 2 different systems and evaluate their efficacy based on the surgical follow-up. METHODS: Thyroid FNA specimens and their corresponding surgical resection specimens were collected between 2007 and 2009. The following diagnostic categories are used in both systems: unsatisfactory/nondiagnostic, benign, follicular neoplasm/suspicious for follicular neoplasm, suspicious for malignancy, and malignant. An additional category termed atypia of undetermined significance/follicular lesion of undetermined significance was used for atypical cases in the 6-tiered system. Statistical analysis was performed by comparing the different diagnostic categories. RESULTS: The case cohort included a total of 7686 thyroid FNA specimens representing 3962 nodules and 3724 nodules, respectively, in the 5-tiered and 6-tiered systems. Negative predictive values for the benign categories (96.9% vs 97.5%; P = 1) and positive predictive values for both the follicular neoplasm categories (26.5% vs 32.1%; P = 2531) and the malignant categories (99.1% vs 99.4%; P = 1) were similar. The most significant differences between the 5-tiered and 6-tiered systems were the percentage of cases classified as benign (83.9% vs 55.4%; P <0001) and as follicular neoplasms (4.6% vs 23.8%; P <0001). It is interesting to note that fewer patients were referred for surgery in the 5-tiered system compared with the 6-tiered one (9.1% vs 36.5%; P <0001). CONCLUSIONS: Use of either the 5-tiered or 6-tiered reporting systems for thyroid FNA specimens can potentially affect the clinical management of patients with thyroid nodules. Cancer (Cancer Cytopathol) 2012;120:117-25. VC 2011 American Cancer Society.

Original languageEnglish
Pages (from-to)117-125
Number of pages9
JournalCancer cytopathology
Issue number2
Publication statusPublished - Apr 25 2012


  • Bethesda
  • Fine-needle aspiration
  • Italian Society for Anatomic Pathology and Cytopathology-International Academy of Pathology (SIAPEC-IAP)
  • Reporting system
  • Thyroid

ASJC Scopus subject areas

  • Cancer Research
  • Oncology
  • Medicine(all)

Fingerprint Dive into the research topics of 'Comparison of 5-tiered and 6-tiered diagnostic systems for the reporting of thyroid cytopathology'. Together they form a unique fingerprint.

  • Cite this

    Bongiovanni, M., Crippa, S., Baloch, Z., Piana, S., Spitale, A., Pagni, F., Mazzucchelli, L., Di Bella, C., & Faquin, W. (2012). Comparison of 5-tiered and 6-tiered diagnostic systems for the reporting of thyroid cytopathology. Cancer cytopathology, 120(2), 117-125.