When Is Thyroidectomy the Right Choice? Comparison between Fine-Needle Aspiration and Final Histology in a Single Institution Experience.

OBJECTIVES: The aim of this study was to compare SIAPEC-IAP-based cytological reports with their corresponding histological diagnoses to establish when thyroidectomy is the right choice in the management of thyroid diseases.

STUDY DESIGN: This is a retrospective review of all the consecutive thyroidectomies/lobectomies performed at Maria Vittoria Hospital during the 10-year period between January 2005 and December 2015. Patients who underwent both fine-needle aspiration (FNA) and surgical procedures in our institution were included in the study.

RESULTS: A total of 260 patients underwent both FNA and a thyroid surgical procedure at Maria Vittoria Hospital; 111 (42.69%) had a malignant histological report. The final cytological diagnosis was nondiagnostic (TIR-1) in 19 cases (7.31%), benign (TIR-2) in 83 cases (31.92%), indeterminate (TIR-3) in 96 cases (36.92%), suspicious for malignancy (TIR-4) in 22 cases (8.46%), and diagnostic for malignancy (TIR-5) in 40 cases (15.38%). Among the 96 cases with TIR-3 cytology, after the review, 44 (16.92%) were classified as TIR-3A and 52 (20%) as TIR-3B. The prevalence of malignancy among TIR-3A cases was 20.45% (9/44) and among TIR-3B cases 53.85% (28/52). The difference was statistically significant (p = 0.0007).

CONCLUSIONS: Our data suggest that follow-up alone is not sufficient in TIR-3A patients given the high prevalence of malignancy within that diagnostic category (20.45%) and the low sensitivity (75.68%) and specificity (59.32%) in the distinction between TIR-3A and TIR-3B. Regarding patients with a multinodular goiter and TIR-2 at FNA, the surgical approach should not be excluded.