Management of the thyroid nodule

Evaluation of cytopathological findings in thyroid nodules with macrocalcification: macrocalcification is not innocent as it seems

Objective Microcalcification is strongly correlated with papillary thyroid cancer. It is not clear whether macrocalcification is associated with malignancy. In this study, we aimed to assess the result of fine needle aspiration biopsies (FNAB) of thyroid nodules with macrocalcifications. Subjects and methods We retrospectively evaluated 269 patients (907 nodules). Macrocalcifications were classified as eggshell and parenchymal macrocalcification. FNAB results were divided into four groups: benign, malignant, suspicious for malignancy, and non-diagnostic. Results There were 79.9% female and 20.1% male and mean age was 56.9 years. Macrocalcification was detected in 46.3% nodules and 53.7% nodules had no macrocalcification. Parenchymal and eggshell macrocalcification were observed in 40.5% and 5.8% nodules, respectively. Cytologically, malignant and suspicious for malignancy rates were higher in nodules with macrocalcification compared to nodules without macrocalcification (p = 0.004 and p = 0.003, respectively). Benign and non-diagnostic cytology results were similar in two groups (p > 0.05). Nodules with eggshell calcification had higher rate of suspicious for malignancy and nodules with parenchymal macrocalcification had higher rates of malignant and suspicious for malignancy compared to those without macrocalcification (p = 0.01, p = 0.003 and p = 0.007, respectively). Conclusions Our findings suggest that macrocalcifications are not always benign and are not associated with increased nondiagnostic FNAB results. Macrocalcification, particularly the parenchymal type should be taken into consideration. Arq Bras Endocrinol Metab. 2014;58(9):939-45

Fine-needle aspiration of thyroid nodules with macrocalcification

BACKGROUND

The presence of microcalcification is highly suggestive of malignancy; however, the association of macrocalcification with cancer remains unclear and controversial. The purpose of this study was to evaluate the diagnostic yield and accuracy of ultrasound (US)-guided fine-needle aspiration (FNA) of thyroid nodules with macrocalcifications and to investigate the association between macrocalcification subtype and malignancy risk.

METHODS

We retrospectively reviewed sonographic findings and pathologic results of thyroid nodules with macrocalcification in patients who underwent US-guided FNA in our hospital from January 2009 through December 2010. Inclusion criteria were as follows: (i) malignant or benign nodules confirmed on histologic examination of surgical specimens after US-guided FNA and (ii) nodules not histologically confirmed that were subjected to FNA at least twice and follow-up US examinations for 2 years. Thyroid nodules with macrocalcification were classified into four groups: smooth total (eggshell) calcification, smooth partial calcification, irregular calcification, and nodular calcification. The diagnostic yield of FNA for thyroid nodules with macrocalcification was determined by cytology. Sensitivity, specificity, and diagnostic accuracy of preoperative FNA cytology were calculated and compared with those of histologic examination of surgical specimens.

RESULTS

There were 188 nodules with macrocalcification in 167 patients; of these, 95 were benign, 80 were malignant, and 13 were nondiagnostic. The diagnostic yield of FNA for thyroid nodules with macrocalcification was 93.08%. Sensitivity, specificity, positive predictive value, and negative predictive value were 98.51%, 90.91%, 95.65%, and 96.77%, respectively. The false-positive value and false-negative value were 9.09% and 1.49%, respectively. The diagnostic accuracy was 96%. There was no statistically significant difference in the association between macrocalcification subtype and malignancy risk (p > 0.05).

CONCLUSIONS

Macrocalcification associated with thyroid nodules is not a reliable criterion for malignancy. FNA of thyroid nodules with macrocalcification had a high diagnostic yield and a reliable accuracy. Consistency between cytology and histology was almost perfect. Therefore, FNA is a good screening method for malignancy of thyroid nodules with macrocalcification.

Fine needle aspiration cytology of Hashimoto's thyroiditis - A diagnostic pitfall with review of literature

Hashimoto's thyroiditis is the second most common thyroid lesion next to goiter diagnosed on fine needle aspiration cytology (FNAC). It is also an important cause for hypothyroidism. FNAC plays a significant role in the diagnosis of thyroid lesions due to its simplicity and low cost. It can accurately diagnose Hashimoto's thyroidits in most patients. However, a small percentage of cases may be missed due to the inherent limitations of this procedure and the varied cytomorphology of this lesion. Therefore thorough cytological evaluation and an integrated approach are necessary to pick up correct diagnosis and to avoid unnecessary surgery. We present a 56-year-old female with solitary thyroid nodule diagnosed as Hurthle cell neoplasm on FNAC, but subsequent histopathological diagnosis following resection revealed Hashimoto's thyroiditis with marked Hurthle cell change.

Comparison of fine needle aspiration cytology and thyroid scan in solitary thyroid nodule

Objective. This was a comparative study between FNAC and thyroid scan used to diagnose the solitary thyroid nodule and histopathology was used as gold standard to compare the results of both modalities. We hypothesized that Fine needle aspiration cytology and thyroid scan diagnose solitary thyroid nodule (STN) as accurately as histopathology. Materials and Methods. This study comprised of 50 patients with solitary thyroid nodules (STN) presented to OPD. After clinical examination these patients were referred to Centre for Nuclear Medicine, Mayo Hospital Lahore for thyroid function tests and thyroid scan (TS). These patients underwent FNAC in the department of Pathology and surgery in Mayo Hospital. The cases were operated and evaluated for histopathological changes. Results. On thyroid scan, 40 patients (80%) having cold nodule were labeled as suspicious 10 patients (20%) had hot nodule. On FNAC 23 patients (46%) had benign lesion, 22 patients (44%) had indeterminate lesion and 5 patients (10%) had malignant lesions. On histopathology, 45 patients (90%) were confirmed to have benign lesions and 5 patients (10%), malignant lesions. After comparison of results of thyroid scan and FNAC with histopathology, the sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy of thyroid scan were 80%, 20%, 10%, 90% and 26%, respectively whereas those of FNAC were 80%, 97.7%, 80%, 97.7% and 96%, respectively. Conclusion. Fine needle aspiration was a significantly better predictor of malignancy than thyroid scan and resulted in a smaller proportion of excisions for benign nodules.

Management of thyroid cancers

Thyroid cancers cover a large spectrum of disease with diametrically opposite prognosis. At one end of the spectrum we have the well differentiated cancers which carry an excellent prognosis, while at the other end there is anaplastic cancer with high mortality rates and dismal prognosis. Management of thyroid cancers still has some controversial issues due to lack of randomized controlled trials. Extent of surgery, extent of neck dissection, role of radioiodine treatment and thyroid stimulating hormone suppression are still debatable. In this review, we highlight these controversial issues and give guidelines for the management and follow up of patients with thyroid cancer.

Diffusion-weighted images differentiate benign from malignant thyroid nodules

PURPOSE

To reveal the possible role of diffusion-weighted images (DWI) in the differential diagnosis of benign and malignant thyroid nodules by comparing the results of fine-needle aspiration cytology (FNAC).

MATERIALS AND METHODS

In an 18-month period (December 2005 to May 2007), 27 cases with benign thyroid nodules with a total of 52 benign nodules, nine cases with thyroid gland malignancy, and 24 healthy control cases were included in the study. Cases that were indicated to undergo to FNAC examination and sent by a clinician for biopsy to the radiology unit were included in the study to assess the cytopathologic confirmation of the clinic, ultrasonographic, and magnetic resonance imaging (MRI) findings.

RESULTS

The mean apparent diffusion coefficient (ADC) values of thyroid nodules were 2745.3 +/- 601.1 x 10(-6) mm(2)/s (1605-3899 x 10(-6)mm(2)/s) in the benign group and 695.2 +/- 312.5 x 10(-6)mm(2)/s (165-1330 x 10(-6)mm(2)/s) in the malignant group. Normal thyroid tissues had mean ADC values of 1344.1 +/- 276.4 x 10(-6) mm(2)/s (1015-1764 x 10(-6)mm(2)/s). The ADC values of three subgroups were significantly different (P = 0.0001). A reduced ADC was observed in most types of malignant tumors due to the consequent decrease of the extracellular extravascular space.

CONCLUSION

Our preliminary results showed that ADC values of nodules may provide useful data about the nature of a thyroid nodule.

An updated audit of fine needle aspiration cytology procedure of solitary thyroid nodule

This study was conducted to see the sensitivity, specificity, and accuracy of fine needle aspiration cytology (FNAC) for solitary thyroid nodules and to compare our experience with that of other regions of the world. It was a prospective cross sectional study conducted on 76 thyroid samples submitted and reported at the Department of Pathology, King Edward Medical University, Lahore. There were 65 (85.5%) females and 11 (14.5%) males. Male to female ratio was 1:5.9. Ages of the patients ranged from 10 to 60 year with mean age 35.37 +/- 12.17. Thirty-three (43.42%) samples were indeterminate. There were 30 cases (39.47%) of benign lesions, comprising of colloid goiter, follicular adenoma, and diffuse hyperplasia. The final reports of these cases were almost the same. On FNAC, 13 cases were declared as malignant (6 cases) or suggestive of malignancy (3 cases) or suspicious for malignancy [4 cases (5.26%)]. Only 9 cases (11.84%) were clearly committed as malignant lesions, comprising of papillary carcinoma, anaplastic carcinoma and suggestive of follicular carcinoma. Comparison of malignant cases on histopathology (14 cases) was close to that of FNAC (13 cases). After comparison of FNAC results with histopathology, overall sensitivity of FNAC was found to be 90%, specificity 87.5%, and accuracy 87%, while positive predictive value (PPV) was 93% and negative predictive value (NPV) was 79.5%. In conclusion, we recommend this procedure in the light of views of other experts as a primary investigation of thyroid lesions. We strongly recommend the suggestion that in a patient with one or more thyroid nodule, FNAC should be advised for every patient for exclusion of cancer. We will also encourage the clinicians to embrace this procedure in the initial management of patients. As FNAC is inexpensive, sensitive, specific, and an accurate procedure it should be adapted as an initial investigation of thyroid diseases in all tertiary hospitals in developing countries like Pakistan.

Surgical trends in the management of thyroid lymphoma

AIMS

To determine the changing trends and current role of surgery for the management of thyroid lymphoma.

METHODS

A retrospective review of 50 surgical patients with a final diagnosis of thyroid lymphoma over a 35-year period.

RESULTS

All patients presented with an enlarging mass, with half having compressive symptoms on presentation. Two-thirds of patients had co-existent histological features of Hashimoto's thyroiditis. Surgery for patients with thyroid lymphoma peaked in the late 1970s (0.79% of all thyroid operations performed) followed by a significant decline in the 1980s with a current frequency of only 0.16% (p=0.009). A larger number of thyroid resections intended as a curative procedure was performed during the first half of this series compared to the latter half (p=0.05). There was no difference in disease-free survival between patients treated by thyroid resection when compared with an open biopsy (p=0.4875).

CONCLUSION

The surgical management of thyroid lymphoma has changed with time. Currently a larger proportion of patients are undergoing surgery in order to achieve a histological diagnosis rather than with therapeutic intent, however, an important role for surgery still exists in the management of a patient with severe airways obstruction.

The role of immunolocalization of CD57 and GLUT-1 in cell blocks in fine-needle aspiration diagnosis of papillary thyroid carcinoma

BACKGROUND

CD57 (Leu7), a marker for natural killer lymphocytes, and glucose transporter-1 (GLUT-1), a facilitative cell surface glucose transport protein, are expressed in a wide spectrum of epithelial malignancies. The usefulness of CD57 and GLUT-1 immunostaining was evaluated as an adjunct to assist in the diagnosis of papillary carcinoma in fine-needle aspirations (FNAs) of the thyroid.

METHODS

Immunohistochemical staining for CD57 and GLUT-1 was performed on paraffin-embedded cell blocks of 50 thyroid FNA cases with the following cytologic diagnoses: 1) papillary carcinoma (15 cases); 2) atypical cytology, cannot exclude papillary carcinoma (14 cases); and 3) benign thyroid (21 cases).

RESULTS

Fourteen of 15 cases with an unequivocal diagnosis of papillary carcinoma were positive for CD57 and 1 case was negative for CD57. Tissue follow-up confirmed papillary carcinoma in all 15 cases. Of the 14 cases with a diagnosis of atypical cytology, cannot exclude papillary carcinoma, 6 cases were positive for CD57 and subsequent excision confirmed papillary carcinoma in all 6 cases. The remaining 8 cases negative for CD57 included surgically confirmed goiter (5 cases), adenoma (2 cases), and papillary carcinoma (1 case). The follicular cells in all 21 cases with a cytologic diagnosis of benign thyroid were negative for CD57. Histologic follow-up of these cases confirmed the benign cytologic diagnoses. GLUT-1 was negative in all cases. The sensitivity and specificity of CD57 was 91% and 100%, respectively.

CONCLUSIONS

CD57 immunostaining is a useful adjunct for the diagnosis of papillary thyroid carcinoma in cell block material. Although negative staining for CD57 does not completely exclude papillary carcinoma, positive staining aids in the accurate diagnosis of malignancy in cytomorphologically equivocal cases. GLUT-1 did not prove to be a useful marker in distinguishing papillary carcinomas.

Ultrasound of thyroid cancer

The management of thyroid nodules is multi-disciplinary and involves head and neck surgeons, pathologists and radiologists. Ultrasound is easy to perform, widely available, does not involve ionizing radiation and is readily combined with fine needle aspiration cytology (FNAC). It is therefore an ideal investigation of choice for evaluating thyroid nodules. It evaluates specific features that help in identifying the nature of the nodule and FNAC helps in diagnostic accuracy. In addition, following treatment for thyroid cancer ultrasound provides a safe tool for disease surveillance. This paper discusses the role of ultrasound in the management of patients with thyroid cancer.

Contemporary management of thyroid cancer

Thyroid cancer is a relatively common and frequently curable malignant neoplasm, accounting for nearly 2% of all new cancers diagnosed annually in the United States. The diagnostic and management options have evolved considerably in the past decade, and a current understanding of these trends in the standard of care have assumed an important consideration in the practices of head and neck surgeons and endocrinologists alike. We sought to review the epidemiology and pathology of the several types of thyroid cancer and to present our evidence-based management algorithm. Every effort was made to offer alternative treatment strategies and supporting data where available. In addition to reviewing well-established approaches to diagnosis and management, emphasis is placed on newer techniques, including minimally invasive thyroidectomy, molecular detection of disease propensity, and the use of recombinant thyrotropin prior to radioiodine ablation.

False-negative fine-needle aspiration cytology results delay treatment and adversely affect outcome in patients with thyroid carcinoma

Clinicians have become reliant on fine-needle aspiration (FNA) cytology in the diagnosis of thyroid nodules. We encountered several patients who had thyroid cancer at operation despite having had FNAs that never showed malignant or suspicious cells. Hence, we retrospectively studied 100 consecutive patients with histologically proven thyroid cancer who had undergone preoperative FNA. Fourteen of these patients had cancers that were not detected by FNA, three of whom developed widespread disease. The sensitivity of FNA was 79%, the false-negative rate 21%, and the inadequate rate 12%. FNA was less sensitive in detecting follicular and Hürthle cell carcinomas compared to papillary carcinomas. FNAs interpreted by cytopathologists at a major university center were more sensitive than those performed elsewhere. A single false-negative FNA delayed surgical treatment by 28 months, sometimes despite clinical evidence suggesting malignancy. Subjects whose tumors were not detected by FNA experienced delayed treatment, had higher rates of vascular and capsular invasion, and were more likely to have persistent disease at follow up (hazard ratio 2.28). False-negative results remain a concern in the cytologic diagnosis of thyroid cancer. Although FNA is a useful test, clinical findings should overrule cytologic data in order for timely treatment to occur.

Pathology tests: is the time for demand management ripe at last?

With the ever increasing demands for pathology testing within the National Health Service there is a need to manage the demand for these tests. This review discusses strategies for the demand management of requests made by clinicians in the disciplines of biochemistry, haematology, and microbiology. The various approaches that have been used to manage demand will be described, along with specific clinical strategies for demand management.

The accuracy of fine-needle aspiration biopsy and frozen section in patients with thyroid cancer

A total of 1076 patients with thyroid nodules were reviewed. The accuracy of fine needle aspiration biopsy (FNAB) and frozen section (FS) were compared and clinical risk factors were analyzed. Our results indicate that 67.9% are benign and 32.1% are malignant with the predominance of papillary thyroid cancer (75.1%). Overall diagnostic accuracy for FNAB and FS were 90.8%-91.2% and 89.1%-90.5%, respectively. There were no significant differences between the diagnostic accuracy on FNAB and FS in all tumors except the follicular adenoma and carcinoma. The diagnostic accuracy of FS was higher than FNAB in patients with follicular adenoma (89.3% vs. 58.9%, p < 0.001) and but lower than FNAB in patients with follicular carcinoma (46.2% vs. 92.3%, p < 0.001). In conclusion, FNAB is cost effective in the preoperative evaluation of thyroid nodule. FS could be eliminated in most cases except with follicular and Hürthle cell neoplasms. FS is valuable when result of FNAB is suspicious or unavailable. FS is more appropriate in deciding the extent of thyroidectomy in follicular neoplasm and FNAB is more reliable initial approach to surgery in patients with Hürthle cell neoplasm. Clinical risk factors may help in selecting patients for surgery but cannot exceed FS in deciding the extent of thyroidectomy in patients with follicular and Hürthle cell neoplasms.

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.

Follow-Up Evaluation and Clinical Course of Patients with Benign Nodular Thyroid Disease

Reliance on fine-needle aspiration biopsy (FNAB) in determining which patients with a thyroid nodule can be observed depends on a low false-negative rate. The purpose of this study was to determine the false-negative rate of FNAB, the utility of routine repeat FNAB, and the clinical course of patients with benign nodular thyroid disease. The records of all patients with nodular thyroid disease evaluated between June 1990 and May 1998 were reviewed. Patients with a benign FNAB were identified, and nodule size, substernal extension, the results of repeat FNAB, clinical course, histologic diagnosis, and length of follow-up were determined. Of the 341 patients referred with nodular thyroid disease, 121 had a benign FNAB. In 80 patients with a mean nodule size of 3.5 ± 1.6 cm, clinical follow-up was recommended. The mean duration of follow-up was 20.5 months for 74 patients, and 6 patients were lost to follow-up. Nodule resolution was observed in 7 patients. Repeat FNAB was performed in 45 patients and was benign in 39 (87%), nondiagnostic in 2 (4%), cellular in 3 (7%), and malignant in 1 (2%). Thyroidectomy was performed in the patients with the cellular and malignant aspirates, and the pathology was adenomatous hyperplasia (2), follicular adenoma (1), and papillary carcinoma (1). Thyroidectomy was performed for increasing nodule size and/or compressive symptoms in 41 patients with a mean nodule size of 5.7 ± 1.9 cm, 19 of whom had substernal extension (P < 0.05). Pathology included benign disease in 39, papillary cancer in 1, and lymphoma arising in Hashimoto's thyroiditis in 1 patient. Given that repeat FNAB was of value in only 1 patient and the false-negative rate for FNAB was only 2.5 per cent, the routine use of repeat FNAB in patients with benign nodular thyroid disease may not be justified. Development of compressive symptoms and diagnosis of unsuspected malignancy in patients with nodule enlargement, including lymphoma in patients with Hashimoto's thyroiditis, underscores the importance of long-term follow-up.

Role of serum thyroglobulin in the pre-operative evaluation of follicular thyroid tumours

AIMS

There is no reliable diagnostic test for pre-operative differentiation between benign and malignant follicular and Hurthle cell neoplasms. Measurements of serum thyroglobulin (Tg) are currently only used post-operatively as a marker of recurrent disease or distant metastases in the follow-up of patient with differentiated thyroid cancer. In this study pre-operative serum Tg measurements were performed with the aim of investigating whether Tg levels differ in benign and malignant follicular and Hurthle cell neoplasms.

METHODS

In 516 patients who underwent thyroid surgery at the Institute of Oncology in Ljubljana, Slovenia, from 1990 to 1996, serum Tg concentration was measured in addition to the standard pre-operative tests (fine-needle aspiration biopsy, ultrasonography, 99mTc scanning and hormonal profile). After the operation, patients were divided into 11 groups based on their histological diagnosis (papillary cancer--classic, papillary cancer--follicular variant, papillary cancer oncocytic variant, occult papillary cancer, follicular adenoma, follicular cancer, Hurthle cell adenoma, Hurthle cell cancer, anaplastic cancer, medullary cancer, nodular goiter) and the serum Tg values of the different groups were compared.

RESULTS

In groups of patients with follicular and Hurthle cell cancer, median Tg values were higher (2895 and 638.5 ng/ml) and, statistically, differed significantly from the serum Tg values in all other groups (P<0.01). Sensitivities and specificities of the tests were 71.8% and 80.4% for follicular cancer and 55.6% and 83.8% for Hurthle cell cancer, while positive and negative predictive values were 75.6% and 77.1% for follicular cancer and 75% and 68.4% for Hurthle cell cancer.

CONCLUSIONS

These results indicate that pre-operative serum Tg measurements might be an important additional diagnostic tool in the pre-operative work-up of patients with thyroid tumours.

Fine-needle aspiration cytology and thyroid surgery in the community hospital

BACKGROUND

To assess the use and usefulness of fine-needle aspiration cytologic biopsy (FNAB) of the thyroid in our hospital.

METHODS

All cytology slides and charts of patients who had FNAB of the thyroid done in our hospital in 1993 were reviewed. Charts of all patients having thyroid surgery in our hospital in 1993 were reviewed to determine the pathological diagnosis and whether FNAB had been performed preoperatively. Finally, we reviewed all consecutive thyroid surgery cases for an 8-year period, and we calculated the yearly percentage of malignancy.

RESULTS

Fifty-five FNAB were done in 53 patients. In 21 patients the FNAB gave indication for thyroid surgery, yet surgery was done in only 12 (57.1%). Forty-two patients had surgery for a thyroid nodule, but only 20 patients (47.6%) had a preoperative FNAB. There were 3 malignancies among the 20; 2 were correctly predicted by FNAB. The FNAB was correct in 18 of 20. In all, 378 thyroid operations were done from 1987 to 1994. The yearly proportion of thyroid malignancy ranged from 11% to 29%, but showed no change corresponding with increasing diagnostic sophistication.

CONCLUSIONS

Fine-needle aspiration cytologic biopsy in the workup of patients with thyroid masses is strikingly underutilized in our institution. While accurate in 90% of cases where used, FNAB appears to play a minor role in the surgeon's decision regarding surgery. As a result of these findings, we developed a grading system for better communication of the FNAB report and a clinical guideline to improve the evaluation of patients with thyroid masses.

Large cystic/solid thyroid nodules: a potential false-negative fine-needle aspiration

BACKGROUND

False-negative fine-needle aspiration (FNA) biopsy results of thyroid nodules are of particular concern because they imply missed malignant lesions. The purpose of this study was to identify characteristics of thyroid nodules that may lead to false-negative cytologic interpretation after FNA.

METHODS

We reviewed 90 consecutive patients who underwent preoperative FNA of thyroid nodules followed by thyroid surgery during a period of 27 months, including their clinical data, type and size of thyroid nodule, FNA cytology results, and final pathology report of the surgical specimen.

RESULTS

Thyroid nodules that had the highest probability of malignancy were those that were large (3 cm or larger), cystic/solid, or large and cystic/solid. The overall false-negative rate for preoperative FNA was 11%. Large, cystic/solid, and thyroid nodules with both characteristics had false-negative rates of 17%, 25%, and 30%, respectively, compared with 0%, 9%, and 17% for small (less than 3 cm), solid, and solid nodules 3 cm or larger, respectively.

CONCLUSIONS

Because of the high prevalence of malignancy in thyroid nodules that are large (3 cm or larger), cystic/solid, or large and cystic/solid and the high false-negative rate of FNA in diagnosing these lesions, thyroid lobectomy for diagnosis should be strongly considered in these patients even when FNA cytologic finding is interpreted as benign.

Fine-Needle Aspiration Biopsy: Use in Diagnosis and Management of Pediatric Thyroid Diseases

Fine-needle aspiration (FNA) biopsy of the thyroid is a reliable, safe, cost-effective, and widely used test. Its introduction and application have had a significant impact in the management of nodular thyroid diseases in adults. However, its utility in pediatric practice is not recognized or emphasized. During the last 12 years we performed 10,971 FNAs; 57 (0.5%) were in patients younger than age 17 years. Among 47 of these biopsies, 66% were benign, 15% were malignant, 6% were suspicious for malignancy and 13% were nondiagnostic. Biopsy was most often (96%) performed for the evaluation of diffuse or nodular goiter. The most common benign cytologic diagnosis was colloid goiter in 17 of 31 patients (55%) and Hashimoto's thyroiditis in 9 of 31 patients (29%). There were no false-positive results and there was one false-negative cytologic result. Among patients who had malignancy proved histologically, nine patients (75%) had papillary thyroid cancer. In this study, FNA biopsy was crucial in deferring surgery in 28 of 47 patients (60%). It is clear that the application of FNA biopsy prevents unnecessary surgery and improves surgical selection of patients with thyroid malignancy. On the basis of our extensive experience, we recommend FNA biopsy as the first diagnostic test for pediatric patients with nodular thyroid lesions.

Fine-needle aspiration biopsy of thyroid nodules: advantages, limitations, and effect

BACKGROUND

The efficacy of fine-needle aspiration (FNA) biopsy and its role in the management of a nodular goiter are clearly established. The accuracy of cytologic diagnosis approaches 95%.

FINDINGS

FNA biopsy is a reasonable approach to thyroid nodules; it has decreased costs substantially because it facilitates selection of patients who need to undergo surgical excision. Selecting patients for operation on the basis of results of FNA biopsy has more than doubled the yield of carcinoma. The limitations of cytologic examination, nondiagnostic results, and cellular follicular neoplasms should be remembered but need not negate continued use of FNA biopsy. Negative (benign) and positive (malignant) cytologic results are conclusive; careful clinical follow-up of benign nodules and surgical excision of malignant nodules are recommended. Nondiagnostic results are inconclusive; further evaluation by repeated FNA biopsy, ultrasound-guided biopsy, or radionuclide scanning is necessary. Suspicious cytologic results are also inconclusive and are associated with a 20% chance of malignant involvement; surgical treatment is necessary for clarification. The role of levothyroxine therapy remains uncertain and is not recommended until compelling data are available.

CONCLUSION

FNA biopsy is a safe, simple, reliable, and cost-effective means of detecting benign nodules. FNA biopsy, not thyroid scanning or ultrasonography, is the preferred initial diagnostic test in all patients with thyroid nodules.