Cumulative Cytological Assessment of Repeated Non-Diagnostic Thyroid Fine Needle Aspirations: A Novel Approach to Reduce Diagnostic Uncertainty.

PURPOSE: Fine needle aspiration (FNA) is the primary diagnostic tool for evaluating thyroid nodules. However, 10%-21% of FNAs yield non-diagnostic (ND) results (Bethesda category I). Repeated ND findings occur in 25%-67.5% of cases, creating diagnostic uncertainty and increased healthcare costs. Our aim was to evaluate whether cumulative analysis of repeated ND cytology samples enables reclassification into a diagnostic Bethesda category.

METHODS

This retrospective observational study (2013-2024) included patients with ≥ 2 ND FNA results from the same thyroid nodule. Two blinded cytopathologists performed cumulative assessment of cellular material from consecutive ND samples to determine if reclassification into diagnostic Bethesda categories was feasible.

RESULTS

Among 1861 FNA procedures, 29 patients (1.56%) had ≥ 2 ND results. Cumulative assessment enabled reclassification in 3/29 patients (10.3%), into Bethesda category II (benign).

FINDINGS: In selected cases, cumulative cytological assessment of multiple ND FNAs may provide sufficient diagnostic material to allow reclassification. This novel cost-effective approach may help reduce diagnostic uncertainty and unnecessary procedures, and improve patient care.