THADA‐IGF2BP3 fusions detected in fine‐needle aspiration specimens of thyroid nodules: An institutional experience

Abstract

AbstractIntroductionThough the clinical significance of THADA‐IGF2BP3 fusions detected in thyroid nodules preoperatively is still under investigation, the limited literature suggests these lesions are clinically low‐risk.MethodsThe pathology archives were searched from 2018 to 2022 for all thyroid nodules with a THADA‐IGF2BP3 fusion detected via ThyroSeqV3® analysis. Patient demographics and tumor characteristics were collected. Statistical analyses were performed and p < .05 was considered statistically significant. This study was approved by the institutional review board.ResultsThe case cohort included 34 thyroid nodules with THADA‐IGF2BP3 fusions from 32 patients (average age—56.1 years, range: 30–86, male to female ratio—10:22). The average nodule size was 3.2 cm (range: 1.3–7.3 cm). At the time of biopsy, 21 cases were diagnosed as atypia of undetermined significance/follicular lesion of undetermined significance, 12 as follicular neoplasm/suspicious for follicular neoplasm and 1 as suspicious for malignancy. Surgical resection was performed in 29 patients (13 partial and 16 total thyroidectomies) to give a total of 31 nodules. Papillary thyroid carcinoma was diagnosed in 19/31 (61%) cases. No cases showed extrathyroidal extension or lymphovascular invasion. The remaining cases were considered either a low‐risk neoplasm or benign. Four cases of NIFTP on final surgical pathology harbored concurrent incidental papillary thyroid microcarcinoma. One patient had the THADA‐IGF2BP3 fusion detected in bilateral nodules.ConclusionsTHADA‐IGF2BP3 fusions can occur in malignant, low‐risk and benign thyroid neoplasms, where malignant neoplasms show lack of aggressive features. Therefore, such entities can be classified as clinically low risk.