Preoperative evaluation and predictive value of fine-needle aspiration and frozen section of thyroid nodules

Prospective analysis of the efficacy of continuous intraoperative nerve monitoring during thyroidectomy, parathyroidectomy, and parotidectomy

OBJECTIVE

Continuous intraoperative electromyographic monitoring was prospectively performed in all parotidectomies, thyroidectomies, and parathyroidectomies over approximately 5 years to assess the efficacy of this technology.

STUDY DESIGN AND SETTING

Continuous intraoperative nerve monitoring with perioperative nerve assessment was performed. The postresection minimal stimulation level of the nerves was determined to evaluate if this level would predict nerve function postoperatively.

RESULTS

Forty-four parotidectomies and 70 thyroid/parathyroid operations were performed with 140 nerves at risk (44 facial, 96 recurrent laryngeal). The incidence of temporary facial paralysis was 15.9% (7 of 44) and the incidence of permanent paralysis was 0%. The incidence of temporary recurrent laryngeal nerve paralysis in terms of nerves at risk was 1.0% (1 of 96), and the incidence of permanent recurrent laryngeal nerve paralysis was 0%. All patients with normally functioning facial and recurrent laryngeal nerves postoperatively had minimal stimulation levels less than or equal to 0.4 mA.

CONCLUSION

Continuous intraoperative nerve monitoring was associated with extremely low rates of temporary and permanent nerve paralysis in our series of 140 nerves at risk as compared to the rates documented in the literature.

Accuracy of fine-needle aspiration of thyroid

CONTEXT

Fine-needle aspiration has become an accepted and cost-effective procedure for rapid diagnosis of thyroid lesions. The routine use of fine-needle aspiration has reduced the rate of unnecessary surgery for thyroid nodules.

OBJECTIVES

To determine the accuracy of fine-needle aspiration biopsy diagnosis and to discuss the possible pitfalls. Design, Setting, and Participants.-Reports of 6226 fine-needle aspiration biopsies of the thyroid performed during a period of 16 years (1982-1998) were reviewed. Computerized reports of the fine-needle aspiration biopsies were sent to the physicians who performed the procedures, and clinical follow-up information regarding the patients was requested. Twenty-four clinicians participated in the study. Histologic diagnoses were available for 354 cases. The cytopathologic diagnoses were correlated with the histologic findings or clinical outcomes.

RESULTS

The cytologic diagnoses were as follows: 210 (3.4%) malignant, 450 (7.2%) suspicious, 3731 (60%) benign, and 1845 (29.5%) unsatisfactory. Most of the cases with negative or unsatisfactory aspirates were followed clinically or by repeat fine-needle aspiration. We identified 11 false-negative and 7 false-positive diagnoses. For aspirates considered sufficient for diagnosis, the sensitivity and specificity levels were 93% and 96%, respectively.

CONCLUSIONS

Fine-needle aspiration of the thyroid gland is highly accurate and has a low rate of false-negative and false-positive diagnoses. The major diagnostic problems are caused by diagnosis using a marginally adequate specimen, diagnosis of malignancy based on just 1 or 2 atypical cytologic features, or overlapping cytologic features of follicular neoplasm with those of follicular variant of papillary carcinoma.

Role of fine-needle aspiration biopsy and frozen section analysis in the surgical management of thyroid tumors

INTRODUCTION

The role of fine-needle aspiration (FNA) and frozen section (FS) in the management of thyroid neoplasms continues to generate considerable controversy. We reviewed our recent experience to determine the clinical utility of FNA and FS in our surgical management and intraoperative decision-making.

METHODS

All patients who had operations for thyroid disease between January 1996 and June 1999 were identified in our prospective database. Completion and incidental thyroidectomies were excluded. Data obtained from the pathology files included FNA, FS, and the final histologic diagnosis.

RESULTS

Five hundred sixty-four patients, including 409 women (73%), with a median age of 50 years (range, 6-94) were identified, of whom 293 (52%) had cancer diagnosed on permanent sections. Three hundred twenty-nine patients (58%) had evaluable FNA, of which 91 (28%) were benign, 94 were malignant (28%), and 144 (44%) were suspicious (46% of these were malignant on final). Frozen section was performed in 397 (70%) patients; of these samples, 170 (43%) were found to be benign, 106 (27%) were malignant, and 121 (30%) were deferred (46% malignant on final). Fine-needle aspiration positively identified 51% of confirmed malignancies; 13% of patients with malignancy had a benign FNA result. Total thyroidectomy was performed in 64% of malignant tumors and 29% of benign thyroid disease (P < .001). Logistic regression revealed no association of extent of surgery with FNA results. A frozen section positive for malignancy was associated with total thyroidectomy (P < .001, RR 6 [CI 3-10]), and a negative frozen section report was associated with lobectomy (P < .05, RR 0.5 [CI 0.3-0.96]). Frozen sections results altered the preoperative plan in only 29 patients (5%).

CONCLUSION

Results of preoperative FNA had no direct impact on the selection of the surgical procedure in this selected cohort. Intraoperative FS added very little to surgical management. The majority of thyroid operations at this institution are planned and performed based on known prognostic factors and intraoperative findings.

Thyroid nodules with FNA cytology suspicious for follicular variant of papillary thyroid carcinoma: follow-up and management

Thyroid nodules diagnosed as follicular neoplasm on fine-needle aspiration biopsy (FNAB) may represent hyperplastic/adenomatous nodules, follicular adenoma or carcinoma, and follicular variants of papillary thyroid carcinoma (FVPTC) on histologic follow-up. In our laboratory, we attempted to identify a subset of cases which showed cellular specimens with focal features (nuclear chromatin clearing, membrane thickening, and rare grooves) suspicious for the follicular variant of papillary thyroid carcinoma. These cases are reported as follicular-derived neoplasms with nuclear features suspicious for FVPTC to distinguish them from those diagnosed as follicular neoplasm. This study documents our experience with 52 cases so diagnosed and followed prospectively with histologic follow-up. A neoplastic nodule was confirmed in 45/52 cases (86%), of which 40 were malignant (77%). FVPTC was identified in 35/52 cases (67%). Four cases were usual papillary carcinoma, 3 were follicular adenoma, 2 were Hürthle-cell adenoma, and 1 was insular carcinoma. In 7 cases, the subsequent histologic findings were nonneoplastic (5 hyperplastic nodules and 2 colloid nodules). Our prospective study shows that in cellular smears from thyroid nodules, a careful search for the nuclear features of papillary carcinoma should be performed, and it is appropriate to diagnose cases as suspicious for FVPTC if the nuclear features of papillary carcinoma are focal. The surgical management of this group may include an intraoperative confirmation of cytologic diagnosis by scrape preparation and/or frozen section in order to avoid a second surgical intervention for completion thyroidectomy.

Thyroid cancer

The management of patients with thyroid cancer can be optimized by developing multidisciplinary groups of highly specialized individuals. The completeness of surgery and its morbidity are mostly surgeon-dependent. Similarly, the decisions regarding selection of adjuvant treatments, doses, follow-up schemes, and so forth require depth of knowledge and understanding of the disease; its variables; factors that govern its course; and the values, limitations, and side effects of alternative therapies.