Malignant thyroid bed mass after total thyroidectomy.

Area of Science:

• Oncology
• Radiology
• Pathology

Background:

• Papillary thyroid carcinoma (PTC) is a common thyroid malignancy.
• Recurrence in the thyroid bed after total thyroidectomy can occur.
• Ultrasonography (US) is a primary imaging modality for surveillance.

Purpose of the Study:

• To assess ultrasonographic (US) criteria for malignant thyroid bed masses post-total thyroidectomy for PTC.
• To investigate the relationship between US findings and fine-needle aspiration (FNA) cytology in thyroid bed masses.

Main Methods:

• Retrospective evaluation of 2,048 patients post-total thyroidectomy for PTC.
• US-guided fine-needle aspiration (FNA) performed on 97 suspicious thyroid bed masses.
• Comparison of US, clinical, and serologic findings between metastatic (n=34) and non-metastatic (n=63) thyroid bed groups.

Main Results:

• Malignant thyroid bed masses were associated with larger tumor size, isthmic position, and prior N1a status.
• US findings of microcalcification/macrocalcification and increased mass height were discriminative for central compartment recurrence.
• Echogenicity, hilum loss, and irregular margins were not significant predictors of malignancy.

Conclusions:

• US criteria for malignant thyroid bed masses differ from those for lateral metastatic nodes.
• Fine-needle aspiration cytology is recommended for suspicious thyroid bed masses, even in low-risk patients, based on specific US findings.