PAPILLARY CARCINOMA OF THE THYROID - CAN OPERATIVE MANAGEMENT BE BASED SOLELY ON FINE-NEEDLE ASPIRATION

BACKGROUND: Fine-needle aspiration cytology is sensitive for detecting malignancies such as papillary carcinoma of the thyroid gland. Becaus e fine-needle aspiration specificity for papillary carcinoma of the th yroid is variable, routine intraoperative frozen section is often advo cated. STUDY DESIGN: To define the roles of fine-needle aspiration and frozen section in papillary carcinoma of the thyroid gland, we review ed data from 82 patients who underwent thyroidectomy between August 19 89 and August 1995 for papillary carcinoma of the thyroid cytology. Re sults of fine-needle aspirations were grouped into three categories: d iagnostic of papillary carcinoma of the thyroid; diagnostic of follicu lar-variant of papillary carcinoma of the thyroid; or suspicious for p apillary carcinoma of the thyroid. Definitive diagnoses were made on p ermanent histology. RESULTS: A fine-needle aspiration revealing papill ary carcinoma of the thyroid was 98 percent specific for cancer or 100 percent specific for follicular-variant of papillary carcinoma of the thyroid. A fine-needle aspiration that was suspicious for papillary c arcinoma of the thyroid (n=24) was only 54 percent specific for cancer . On the basis of gross intraoperative findings, 5 of these 24 patient s underwent total thyroidectomy without frozen section, and all had ca rcinoma. The other 19 had frozen section analysis. Of the 5 patients w ith cancer detected by frozen section, 4 had cancer on permanent histo logy. Findings on frozen section demonstrated a follicular neoplasm in the other 14 patients, of which 4 ultimately were cancer. CONCLUSIONS : When papillary carcinoma of the thyroid or follicular-variant of pap illary carcinoma of the thyroid is definitively diagnosed on fine-need le aspiration, the surgeon can perform definitive thyroidectomy withou t frozen section because of the high specificity for cancer. If the fi ne-needle aspiration is suspicious for papillary carcinoma of the thyr oid, the incidence of cancer is 54 percent, and patients with these co nditions should undergo surgery with frozen section. When either gross findings or frozen sections suggest malignancy, definitive thyroidect omy can be performed because 90 percent of such cases will be cancer. If frozen section is not diagnostic of malignancy, a thyroid lobectomy /isthmusectomy is recommended because 71 percent have a benign lesion. This systematic approach to papillary carcinoma of the thyroid will o bviate unnecessary frozen sections while maintaining excellent diagnos tic specificity.