LAUSR

Background. The reclassification of noninvasive encapsulated follicular variant of papillary thyroid cancer to noninvasive follicular thyroid neoplasm with papillary‐like nuclear features will reduce nonefficacious and potentially harmful care. Reclassification is estimated in 18.6% of patients with papillary thyroid carcinoma; we aimed to quantify the implications of this change. Methods. Pathology reports from April 2006 to April 2016 were reviewed to isolate cases that would have been designated as neoplasm with papillary‐like nuclear features. Of the 1,335 cases of papillary thyroid carcinomas, 194 cases (14.5%) met criteria. Cases in which neoplasm with papillary‐like nuclear features was found in combination with other thyroid malignancies (n = 25) and cases of prior thyroid lobectomy (n = 5) were excluded. Demographic, pathologic, treatment, and follow‐up data were assessed for the remaining 164 potential neoplasm with papillary‐like nuclear features cases. Logistic regression analysis was performed to evaluate association between fine‐needle aspiration result and index procedure. Results. Of the 164 patients with tumors who met neoplasm with papillary‐like nuclear features criteria, fine‐needle aspiration results were nondiagnostic (2%), benign (18%), atypia/follicular lesion of undetermined significance (26%), follicular neoplasm or suspicious for follicular neoplasm (20%), suspicious for malignancy (19%), malignant (6%), and not obtained (9%). Eighty‐five (52%) patients underwent total thyroidectomy. A “suspicious for malignancy” fine‐needle aspiration result was associated with undergoing total thyroidectomy versus thyroid lobectomy (P = .006). Thyroid lobectomy was the index procedure for 79 patients (48%); of these patients, 54% (n = 43, 3.2% of all patients with papillary thyroid carcinomas) underwent subsequent total thyroidectomy, and 24% received postoperative radioactive iodine treatment. There were no recurrences among the 125 patients with >3 months of follow‐up. Conclusion. The reclassification of noninvasive encapsulated follicular variant of papillary thyroid cancer as neoplasm with papillary‐like nuclear features will decrease nonefficacious treatment and reduce costs. However, the impact of this change with regard to extent of surgery was limited to 3.2% of patients with papillary thyroid carcinomas compared with the projected potential impact on 18.6%.