Fine-needle aspiration biopsy diagnosis of follicular variant of papillary thyroid cancer: therapeutic implications.

Objective: Frozen-section analysis of follicular lesions is often inconclusive because capsular or vascular invasions are the hallmarks of malignancy with this technique and may not be seen in the particular field studied. Using preoperative fine-needle aspiration biopsy specimens, we attempted to identify malignant follicular lesions and compare these results against frozen-section analysis.

Methods: A retrospective study of 1000 consecutive thyroid fine-needle aspiration biopsy specimens was performed. Surgical pathologic correlation was available in 179 cases.

Results: Fine-needle aspiration biopsy yielded a suspicious or positive rate of 23%. Surgical pathology was available in 179 patients, of which 95% had thyroid cancer. The follicular variant of papillary cancer was identified in 26 cases, or 15% of the positive cases. Frozen-section analysis yielded false-negative results in 7 of these 26 cases (27%).

Conclusions: Preoperative recognition of the follicular variant of papillary cancer by fine-needle aspiration biopsy may reduce the overall incidence of false-negative frozen-section findings.