Is galectin-3 a good method for the detection of malignancy in patients with thyroid nodules and a cytologic diagnosis of "follicular neoplasm"? A critical appraisal of the evidence.

BACKGROUND: Thyroid nodules are the most common surgical disease of the thyroid. Fine-needle aspiration biopsy (FNAB) is the most commonly employed tool for establishing a diagnosis. However, 15% to 25% of FNAB reports yield inconclusive results. Immunostaining of cytological smears from FNAB with galectin-3 has been proposed as a tool for differentiating between benign and malignant nodules. We performed a systematic review to evaluate the utility of galectin-3. METHODS: Prospective studies of nodules with FNAB reports of "follicular neoplasm" and with a definitive diagnosis confirmed by histopathology were selected. Calculations of individual sensitivity, specificity, and positive and negative likelihood ratios were made. RESULTS: The articles selected were those with the best methodological quality. CONCLUSION: Galectin-3 could be a good tool to guide therapeutic decision in patients with thyroid nodules and FNAB results of follicular neoplasm, but available information has methodological flaws that precludes a definitive answer about galectin-3 utility in the clinical setting.