The Underestimated Risk of Cancer in Patients with Multinodular Goiters After a Benign Fine Needle Aspiration

Importance Ultrasound-guided fine needle aspiration (FNA) is an excellent tool for evaluating patients with solitary thyroid nodules, with a false-negative malignancy rate of <3 %. The utility of FNA in patients with a cervical multinodular goiter (MNG) is unknown, because biopsy and surveillance of thyroids with numerous nodules may be impractical. Objective To evaluate the incidence and risk factors for unsuspected thyroid cancer on final pathology in patients with a non-functional, cervical MNG who had a benign preoperative FNA and underwent thyroidectomy. Design, setting and participants Retrospective review of patients with non-functional, cervical MNG at a high-volume tertiary referral center between 2005 and 2012. Main outcome measure(s) Incidence of thyroid cancer on surgical pathology. Results Of the 134 patients included in the study, 31 (23.1 %) were found to have thyroid cancer on final pathology. Twenty-one (15.7 %) patients had a microscopic papillary cancer (<1 cm) and 10 (7.5 %) patients had other forms of thyroid cancer [five follicular, four papillary (>1 cm), and one patient with a papillary and follicular cancer]. On univariate analysis, male gender had a near-significant association with non-micropapillary thyroid cancer (p = 0.06). On multivariate analysis, male gender (OR = 10.2, 95 % CI 1.35-76.8) and FNA cytology not reviewed at our institution (OR = 6.0, 95 % CI 1.2-30) were independently associated with non-micropapillary thyroid cancer. Conclusions and relevance The incidence of thyroid cancer in patients with MNG and benign FNA is significant. Men and patients in whom the FNA cytology is not reviewed by an experienced cytopathologist may be at an increased risk for an undetected thyroid cancer.