Fine-Needle Aspiration Optimizes Surgical Management in Patients With Thyroid Cancer
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- Greenblatt, D.Y., Woltman, T., Harter, J. et al. Ann Surg Oncol (2006) 13: 859. doi:10.1245/ASO.2006.08.020
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Fine-needle aspiration (FNA) is accurate in diagnosing papillary, medullary, and anaplastic thyroid cancer, as well as lymphoma. Although many surgeons routinely perform FNA before surgery, some question whether FNA influences operative management. Therefore, to determine whether FNA affects surgical management in patients with thyroid cancer, we reviewed our experience.
A total of 442 consecutive patients underwent thyroid surgery at 1 academic center. Of these, 411 had surgery for an index nodule in the absence of previous radiation or familial thyroid cancer. FNA, operative, and permanent histology findings were reviewed.
The average patient age was 46 years, and 79% were female. A total of 211 patients (51%) had a preoperative FNA, and 71 (17%) had a final diagnosis of cancer. The sensitivity and specificity of FNA for thyroid cancer were 89% and 92%, respectively. In the FNA group, 1 (2.4%) of 41 patients with papillary thyroid cancer required completion thyroidectomy. In contrast, in the no-FNA group, 4 (40%) of 10 patients with papillary thyroid cancer required a second operation. No patient in the FNA group received thyroid resection for lymphoma, whereas three (100%) of three patients with lymphoma in the no-FNA group were treated surgically. A total of 98% of the FNA group, compared with 54% of the no-FNA group, received optimal surgical treatment for thyroid cancer.
FNA is a sensitive and specific test for the diagnosis of thyroid cancer, allowing definitive initial surgery and avoiding unnecessary procedures. Therefore, we recommend routine use of preoperative thyroid FNA, even in those patients in whom a resection is already planned.
KeywordsThyroid neoplasmsThyroid lymphomaThyroid surgeryFine-needle aspiration
Einhorn and Franzen1 of Sweden described a new diagnostic technique in 1962 in the article titled “Thin-Needle Biopsy in the Diagnosis of Thyroid Disease.” Thyroid fine-needle aspiration (FNA) biopsy did not become widespread in the United States until the 1980s. The procedure, which is inexpensive and easily performed in the clinic, soon became an important tool in the evaluation of thyroid disease.
There is a large body of literature on the merits of FNA for the identification of thyroid malignancy.2–13 FNA is accurate in diagnosing papillary (PTC), medullary (MTC), and anaplastic thyroid cancer, as well as thyroid lymphoma. An FNA diagnosis of cancer allows the surgeon to plan a definitive initial operation for patients with PTC or MTC. Furthermore, patients with an FNA diagnosis of anaplastic cancer or lymphoma may avoid unnecessary surgery and proceed directly with medical therapy. For these reasons, most surgeons routinely perform FNA before thyroid surgery. However, some question whether FNA influences operative management.14 Therefore, to determine whether FNA affects surgical management in patients with thyroid cancer, we reviewed our experience.
A review of the University of Wisconsin Hospital operative database identified 442 consecutive patients who underwent thyroid surgery from January 1995 to April 2001. Thirty-one patients were excluded from the study for the following reasons: previous thyroid surgery (18 patients), history of neck radiotherapy (2 patients), and history of a familial thyroid cancer syndrome (11 patients). For the remaining 411 patients, cytopathologic, operative, and histopathologic findings were reviewed.
FNA results were grouped into the following categories: none, indeterminate, benign, suspicious for follicular or Hürthle cell neoplasm (SF), suspicious for malignancy (SM), and malignant. FNAs described as “indeterminate,” “unsatisfactory,” and “nondiagnostic” were coded as indeterminate. A report containing the diagnosis “benign,” “goiter,” “cyst,” “adenoma,” or “no evidence of malignancy” was recorded as benign. FNA reports that were “suspicious” or “atypical” with features suggestive of “follicular neoplasms” or “Hürthle cell neoplasms” were coded as SF. FNAs that were “suspicious for malignancy” but with no mention of follicular or Hürthle cell neoplasms were coded as SM. FNAs read by the pathologist as unequivocally malignant were coded as malignant. These FNA results were reviewed by a single cytopathologist.
Permanent pathologic diagnoses were coded as malignant for any report of PTC, MTC, or follicular, Hürthle cell, or anaplastic thyroid carcinoma. Lymphomas and metastatic disease of the thyroid were also recorded as malignant. A size cutoff of 8 mm was used for PTCs—tumors ≥8 mm in diameter were coded as malignant true PTCs, and those < 8 mm were coded as benign. All other diagnoses were coded as benign, including adenoma, goiter, thyroiditis, Hürthle cell adenoma, and hyperplasia.
FNA results were compared with permanent histological examination results for determinations of sensitivity, specificity, and predictive value. For these calculations, benign and indeterminate FNAs were considered negative test results, SM and malignant results were considered positive, and SF results were disregarded. The use of preoperative FNA was a decision made by the surgeon.
Statistical analysis was performed by analysis of variance (SPSS; SPSS Inc., Chicago, IL). Significance was defined as a P value of < .05.
Average age (y)
No. with cancer (%)
Patients with cancer
In the FNA group, 1 (2.4%) of 41 patients with PTC required a completion thyroidectomy. In contrast, in the no-FNA group, 4 (40%) of 10 patients with PTC required reoperation for completion thyroidectomy. The difference was statistically significant.
In the FNA group, there were two patients with MTC. The diagnosis was made in both cases by FNA. The patients received total thyroidectomy, and neither patient required further surgical treatment. No patient in the no-FNA group had MTC.
None of the patients with thyroid lymphoma in the FNA group received thyroidectomy, whereas three (100%) of three in the no-FNA group did. This difference was also statistically significant.
Optimal surgical treatmenta for PTC, MTC, and lymphoma
42 of 43
7 of 13
Many authors have recommended FNA as an important test for the evaluation of thyroid nodules.2–5,7 The technique is safe and conveniently performed in the office setting. FNA is of limited utility for the diagnosis of follicular thyroid cancer because it is unable to identify the hallmark features of malignancy, including vascular and capsular invasion.15 However, the technique is highly accurate in the diagnosis of PTC, MTC, and anaplastic carcinomas, as well as of thyroid metastases and lymphoma. The widespread adoption of FNA has led to a decrease in diagnostic thyroidectomy.
Identification of a thyroid malignancy allows the planning of definitive therapy, be it surgical, as for PTC and MTC, or nonsurgical, as for anaplastic carcinoma and thyroid lymphoma. Although many surgeons routinely perform FNA before thyroid surgery, some authors have questioned the value of the test in influencing surgical management. For example, the group at the Memorial Sloan-Kettering Cancer Center has reported that preoperative FNA has no direct effect on their selection of surgical procedure.14 Instead, they rely on known prognostic factors and intraoperative findings to plan and perform thyroid operations. In our experience, FNA is a valuable tool in planning the operative management of thyroid cancer. We present in this article our data for FNA in the diagnosis of PTC, MTC, and thyroid lymphoma.
PTC is the most common type of thyroid cancer. Although some controversy exists over the operative treatment of PTC, we recommend total thyroidectomy rather than lobectomy.16 Foci of PTC are found in both thyroid lobes in 35% to 85% of patients with PTC.17–20 Up to 10% of PTC recurrences occur in the contralateral lobe if not initially resected.21 Although no study has demonstrated a survival difference, several retrospective studies have shown a reduction in the risk of local recurrence in patients treated with total thyroidectomy compared with lesser resections.22–25 Removal of all thyroid tissue allows the use of radioiodine to detect and treat metastatic disease. Furthermore, thyroglobulin may be monitored as a marker of disease recurrence.
In this study, 42 (98%) of 43 patients with PTC or MTC in the FNA group were treated with total thyroidectomy as the initial operation. One patient (2%) in the FNA group required a completion thyroidectomy for PTC. This patient had preoperative FNA and intraoperative frozen-section biopsies that were both negative for PTC, but the final histopathologic diagnosis was PTC. By contrast, 40% of the patients with PTC in the no-FNA group required completion thyroidectomy. Thus, although completion thyroidectomy is not entirely eliminated in patients with preoperative FNA, the need is markedly lower. The need for a second operation results in an increased cumulative risk for complications such as bleeding,26 hypoparathyroidism,27 and recurrent laryngeal nerve injury,26,28,29 as well as increased cost and patient inconvenience. In our opinion, the patients who did not receive preoperative FNA and eventually required completion thyroidectomy for PTC received suboptimal surgical care.
Primary thyroid lymphoma (PTL) is an uncommon malignancy. It accounts for < 4% of all extranodal non-Hodgkin’s lymphomas and 5% of thyroid malignancies.30–34 PTLs typically occur in middle-aged and older women and arise in the setting of autoimmune thyroiditis. The relative risk of a patient with lymphocytic thyroiditis developing lymphoma has been estimated to be 40 to 80 times greater than in the general population.35–37
In the past, thyroid lymphoma was thought to be a form of anaplastic thyroid carcinoma, and it was treated with radical thyroid resection.30,38–40 As the benefit of radiation and chemotherapy in PTL became evident, thyroidectomy became less common as a treatment, although other invasive procedures were still necessary to establish the diagnosis.31,34,41–53 With the widespread adoption of FNA in the diagnosis of systemic lymphomas, several authors began to discuss whether the technique could be used for PTLs, thus obviating the need for any surgical intervention.43,47,54,55 Advances in immunophenotypical analysis, including flow cytometry and immunohistochemistry, have improved the accuracy of FNA in diagnosing thyroid lymphoma, thus making invasive surgical diagnostic procedures generally unnecessary.56
In this study, three patients (100%) with PTL in the no-FNA group underwent thyroid operations. Two had lobectomies, and one had a total thyroidectomy. Thyroid surgery was probably not of benefit for these patients. FNA, had it been performed, could have resulted in an earlier diagnosis of PTL, more rapid definitive therapy, and the avoidance of unnecessary surgery.
In some cases, however, the diagnosis of PTL cannot be made with noninvasive techniques. One patient in the FNA group received a final diagnosis of thyroid lymphoma. This patient underwent an FNA and a core needle biopsy, both of which were nondiagnostic. The patient was taken to the operating room for incisional biopsy, and frozen-section analysis was positive for lymphoma. No further resection was performed, and the patient was referred for medical treatment.
Our data demonstrate that FNA improves surgical outcomes in patients with thyroid cancer. In our series, 98% of the patients with PTC, MTC, and thyroid lymphoma received optimal surgical treatment—defined as no need for completion thyroidectomy for PTC and MTC and as no unnecessary surgery for lymphoma—in the FNA group, compared with only 54% in the no-FNA group.
In conclusion, FNA is a sensitive and specific technique for the identification of thyroid malignancy and other diseases such as follicular neoplasms that require surgery. FNA is an important tool for the diagnosis of cancer, allowing definitive initial surgery for PTC and MTC and the avoidance of unnecessary operations for thyroid lymphoma. Therefore, we recommend routine use of preoperative thyroid FNA, even in patients in whom a resection is already planned.