The 2017 Bethesda System for Reporting Thyroid Cytopathology

Area of Science:

• Cytopathology
• Endocrinology
• Oncology

Background:

• The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) provides a standardized framework for thyroid fine-needle aspiration (FNA) specimen analysis.
• The 2017 revision maintains the established six diagnostic categories for thyroid FNA reports.

Framework:

• The six diagnostic categories are: nondiagnostic/unsatisfactory, benign, atypia/lesion of undetermined significance, follicular neoplasm/suspicious for follicular neoplasm, suspicious for malignancy, and malignant.
• Laboratories select one preferred term for categories with dual nomenclature (e.g., AUS/FLUS), ensuring consistent interpretation.
• Synonymous terms are not used to denote distinct pathological entities.

Implementation:

• The 2017 revision updates malignancy risk stratification for each category based on recent data (post-2010).
• Evidence-based clinical management recommendations are linked to the updated malignancy risks associated with each category.
• Diagnostic criteria and optional notes are adjusted to account for the reclassification of noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP).

Implications:

• Standardized reporting improves diagnostic consistency and facilitates appropriate patient management.
• Updated risk stratification and management guidelines enhance clinical decision-making for thyroid nodules.
• Consideration of NIFTP in diagnostic criteria refines malignancy risk assessment and guides surgical interventions.