Utility of Preoperative Ultrasonography in Transferred Patients with Suspicious Malignancy on Ultrasonography-Guided Fine-Needle Aspiration Cytology of Thyroid Nodules: A Single-Center Retrospective Study

BACKGROUND: This study aimed to assess the utility and characteristics of preoperative ultrasonography (US) in patients transferred to referral hospitals from local clinics with a diagnosis of malignancy on US-guided fine-needle aspiration cytology of thyroid nodules. MATERIAL/METHODS: From January 2018 to June 2018, 109 transferred patients underwent preoperative US in our hospital for suspected thyroid malignancy on cytological analysis after US-guided fine-needle aspiration of thyroid nodules in local clinics. Preoperative US was performed by a single radiologist in all patients. Among them, 6 were excluded from the study because of refusal of thyroid surgery. Preoperative US and histopathological results were compared in all patients. RESULTS: After thyroid surgery, pathological examination revealed papillary thyroid carcinoma (PTC) (n=98), follicular adenoma (n=1), and nodular hyperplasia (n=4). Of the 103 patients, 91 exhibited suspicious US findings on the preoperative US, whereas 12 did not. In the 91 patients with suspicious US findings, PTC (n=90) and follicular adenoma (n=1) were confirmed after thyroid surgery. In the 12 patients with no suspicious US findings, PTC (n=8) and nodular hyperplasia (n=4) were confirmed after thyroid surgery. On repeat analysis of the cytological slides of the 4 nodular hyperplasia cases from the local clinics, Bethesda category II (n=1) and III (n=3) were determined. CONCLUSIONS: In the transferred patients with a malignant cytology, preoperative US might be helpful to detect false-positive cytology cases.