Do large thyroid nodules (≥4 cm) without suspicious cytology need surgery?

Area of Science:

• Endocrinology
• Oncology
• Pathology

Background:

• Fine-needle aspiration biopsy (FNAB) is a standard diagnostic tool for thyroid nodules.
• High false-negative rates of FNAB for giant thyroid nodules (>4 cm) pose diagnostic challenges.
• Surgical resection is often recommended for nodules >4 cm due to increased malignancy risk and FNAB limitations.

Purpose of the Study:

• To evaluate the feasibility of surgical resection for thyroid nodules >4 cm.
• To determine the incidence of malignancy in thyroid nodules >4 cm with non-suspicious FNAB cytology.
• To assess the diagnostic accuracy of FNAB for large thyroid nodules.

Main Methods:

• Retrospective analysis of 453 patients with thyroid nodules >4 cm.
• Data collected from January 2017 to August 2022 at Severance Hospital, Seoul.
• Analysis included preoperative FNAB results and final surgical pathology findings.

Main Results:

• Of 453 patients, 140 nodules were benign and 119 indeterminate by FNAB.
• Final pathology revealed malignancy in 38.9% of cytologically benign and 55.5% of indeterminate nodules >4 cm.
• Follicular carcinoma and its variants comprised a significant portion of malignancies in both benign and indeterminate cytology groups.

Conclusions:

• Preoperative FNAB demonstrates high false-negative rates and low diagnostic accuracy for thyroid nodules >4 cm without suspicious cytology.
• Diagnostic surgery should be considered a viable treatment option for these large nodules.
• This approach aids in accurate diagnosis and management of potentially malignant large thyroid nodules.