Sonographic and pathologic features of malignant hot thyroid nodules: A multi-institutional study

Area of Science:

• Endocrinology
• Oncology
• Radiology

Background:

• Hot thyroid nodules, typically benign, can present with suspicious sonographic features.
• Malignancy occurs in approximately 5% of hot thyroid nodules.

Purpose of the Study:

• To investigate the incidence, sonographic characteristics, and surgical pathology of malignancy in hot thyroid nodules.
• To guide the workup and pre-procedure assessment for thermal ablation of these nodules.

Main Methods:

• Retrospective analysis of 323 hot nodules from 257 patients undergoing thyroidectomy across 5 centers (2017-2024).
• Correlation of ultrasonography findings with thyroid uptake scans.
• Assessment of sonographic features using the Thyroid Imaging Reporting and Data System (TI-RADS) classification.

Main Results:

• Malignancy was found in 3.4% of hot nodules (11/323), with a higher rate in solitary toxic nodules (7.3%) versus toxic multinodular goiters (1.0%).
• Malignant nodules were more frequently solid, isoechoic/hyperechoic, and biopsied compared to benign ones.
• Pathology revealed papillary and follicular cancers with adverse features like lymphovascular invasion and tall cell variants.

Conclusions:

• Solitary toxic nodules present a greater malignancy risk than toxic multinodular goiters.
• Malignancies in solitary toxic nodules can display poor prognostic pathological features.
• The observed malignancy rate supports biopsy recommendations before thermal ablation of solitary toxic nodules.