Variability in the atypia of undetermined significance/follicular lesion of undetermined significance diagnosis in the Bethesda System for Reporting Thyroid Cytopathology: sources and recommendations

Acta Cytol. 2011;55(6):492-8. doi: 10.1159/000334218. Epub 2011 Dec 9.

Abstract

Objective: Of the 6 categories in the Bethesda System for Reporting Thyroid Cytopathology (BSRTC), the atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS) category has received the most attention. The objectives of this study were to review the use of the AUS/FLUS category in recent studies, to search for likely sources of the variability in its use, and to address possible methods for improvement.

Study design: A PubMed search was performed to retrieve peer-reviewed articles that have comprehensively detailed the incidence and outcome of AUS/FLUS and other BSRTC categories. Related thyroid cytology articles on the BSRTC were also included.

Results: Recent series that reported experiences with the BSRTC categories showed that the AUS/FLUS category exhibited a marked variability in incidence (0.7-18%) and malignant outcome (6-48%) in resection specimens. Review of the literature revealed institutional differences in technical aspects, interpretation and application of criteria, analysis of outcome data, and clinicopathologic interactions.

Conclusions: A heightened awareness of technical issues, diagnostic borders of AUS/FLUS, and clinical management may aid in diagnostic refinement and help avoid overuse of this category.

Publication types

  • Review

MeSH terms

  • Biopsy, Fine-Needle
  • Cell Transformation, Neoplastic / pathology*
  • Databases, Bibliographic
  • Diagnostic Errors*
  • False Negative Reactions
  • Humans
  • Prognosis
  • Risk
  • Specimen Handling
  • Terminology as Topic
  • Thyroid Gland / pathology*
  • Thyroid Nodule / classification
  • Thyroid Nodule / diagnosis*
  • Thyroid Nodule / pathology*