Pathologist-performed ultrasound-guided fine needle aspiration biopsies of extrathyroidal sites: An observational...

Pathologist-performed ultrasound-guided fine needle aspiration (USFNA) biopsies have become an increasingly important component of the interventional cytopathologist's toolbox. However, its application varies between institutions, and there is limited literature describing its performance characteristics when utilized in extrathyroidal sites. Here we review our institutional experience within our pathologist-run FNA clinic.

A retrospective review was conducted of pathologist-performed USFNAs of extrathyroidal sites over a 9-year period. Data collected included lesion site, size, patient age, patient gender, diagnostic category, and corresponding results from surgical resection when available. The diagnosis on surgical resection was considered the gold standard for determining discordance rates.

A total of 143 pathologist-performed USFNAs of extrathyroidal lesions were performed from October 2011 to October 2020. These encompassed a wide range of sites, with most biopsies from the head and neck. The mean recorded size was 2.2 cm, with a range of 0.6-6 cm. Larger lesions (over 2 cm) were more likely to be noted in challenging locations, demonstrate difficult features, or be cystic. Most (n = 133) biopsies were sufficient for diagnosis, with a non-diagnostic rate of 7% (n = 10). Accuracy when compared to subsequent surgical resection was high, with sensitivity of 89%, specificity of 93%, positive predictive value of 94%, and negative predictive value of 87%.

Our experience supports that pathologist-performed USFNA of extrathyroidal lesions-even those with challenging features-can result in excellent diagnostic yield and accuracy. The addition of USFNA to the interventional cytopathologists' repertoire can be a valuable tool to enhance patient care.