A Novel Scoring System for AUS Thyroid Nodule.

Area of Science:

• Endocrinology
• Cytopathology
• Oncology

Background:

• Thyroid nodules classified as Bethesda III atypia of undetermined significance (AUS) present diagnostic challenges.
• Accurate risk stratification is crucial for appropriate patient management and avoiding unnecessary procedures.

Purpose of the Study:

• To subclassify Bethesda III AUS thyroid lesions using fine-needle aspiration cytology (FNAC).
• To develop and validate a novel scoring system for estimating malignancy risk in Bethesda III subcategories.

Main Methods:

• Retrospective analysis of 338 thyroidectomy cases with Bethesda III FNAC findings.
• Subclassification of Bethesda III into six subtypes (III-A to III-F).
• Development of a scoring system integrating cytological, radiological, and clinical factors.

Main Results:

• Malignancy rates varied significantly across subcategories, with III-B showing the highest (54.73%).
• Cytological subcategory and high-risk ultrasound features were significantly associated with malignancy (p < 0.05).
• The proposed scoring system effectively stratified patients into low, moderate, and high malignancy risk groups.

Conclusions:

• Subclassification of Bethesda III AUS nodules improves malignancy risk assessment.
• The novel scoring system offers a practical tool for guiding individualized thyroid nodule management.
• Further prospective studies are needed to validate the scoring system's predictive value.