Predictors of Nondiagnostic Cytology in Surgeon‐Performed Fine‐Needle Aspiration Biopsy of Thyroid Nodules

Abstract

Objectives: (1) List the factors that are predictive of non-diagnostic cytology in surgeon-performed ultrasound-guided fine-needle aspiration (FNA) of thyroid nodules. (2) Describe a patient cohort that may benefit from early referral to other clinicians. Methods: Retrospective chart review. Patients included all adults who underwent thyroid nodule FNA by a staff, fellow, or resident otolaryngologist at our center between January 2011 and June 2013. Cytology was interpreted by a staff cytopathologist according to the Bethesda classification system. The predictive factors analyzed were patient age, sex, body mass index (BMI), thyroid gland size, thyroid function, presence of multinodular goiter, presence of Graves’ disease or thyroiditis, nodule size, location, vascularity, echogenicity, calcifications, cystic component, level of performer training, and level of FNA experience. Results were analyzed using chi-squared, Fisher exact test, or unpaired t test. Results: A total of 190 patients were reviewed, for a total of 301 nodules. The average age was 53 years, with an 88% female predominance. The overall nondiagnostic rate was 23%. Nodules with a predominant cystic component and those less than 1 cm were more likely to yield nondiagnostic cytology ( P = .04, P = .05, respectively). FNA performed by a trainee with experience of less than 50 FNA were also more likely to yield nondiagnostic cytology ( P = .04). No other factors significantly influenced the nondiagnostic rate. Conclusions: Cystic nodules and nodules less than 1 cm are more likely to yield non-diagnostic cytology in surgeon-performed thyroid FNA. Caution should be used in trainee-performed FNA for which the nondiagnostic risk is high. These patients may benefit from early referral to other clinicians.