Circulating thyrotropin receptor messenger RNA for evaluation of thyroid nodules and surveillance of thyroid cancer in children

PurposeThe aim of this study was to determine the role of thyrotropin receptor messenger RNA as a novel blood test for evaluation of thyroid nodules and cancer in children.MethodsWe reviewed thyroid disease management of patients younger than 18 years with thyrotropin receptor messenger RNA measurements identified from a prospective, institutional review board-approved registry during 2008 to 2010.ResultsThirty-nine thyrotropin receptor messenger RNA measurements were made in 21 female patients (12-17 years old; median, 16 years). Four patients with fine-needle aspiration only had benign thyroid cytology, and 3 of 4 had undetectable thyrotropin receptor messenger RNA. Seventeen patients underwent 22 thyroid operations. Preoperative thyrotropin receptor messenger RNA was measured in 9 patients: 3 of 4 with thyroid cancer had elevated levels and 3 of 5 with goiters undetectable. Postthyroidectomy surveillance (median, 16 months; range, 6-24) of 11 thyroid cancer patients (8 papillary, 3 follicular) showed that thyrotropin receptor messenger RNA was concordant with thyroglobulin in 14 (73%) of 19 measurements. In 3 (16%) of 19 measurements, thyrotropin receptor messenger RNA was the only blood test useful for disease assessment because of elevated antithyroglobulin antibodies. Overall, to predict thyroid cancer, thyrotropin receptor messenger RNA demonstrated 73% sensitivity, 82% specificity, 62% positive predictive value, 88% negative predictive value, and 79% accuracy.ConclusionThyrotropin receptor messenger RNA provides complementary evaluation to thyroglobulin and fine-needle aspiration for pediatric thyroid nodule management.     

The results of ultrasound-guided fine-needle aspiration biopsy for evaluation of nodular thyroid disease

BACKGROUND: The purpose of this study was to determine whether ultrasonography (US) improves the accuracy and reduces the rate of nondiagnostic fine-needle aspiration biopsy (FNAB) of thyroid nodules. METHODS: A review of 536 consecutive patients evaluated for nodular thyroid disease from 1990 to 2001 was completed to determine the results for US vs palpation-guided FNAB. RESULTS: FNAB was used to evaluate 458 patients. US-guided FNAB was performed in 66 (12%) patients: 48 with a nonpalpable nodule, 14 with nondiagnostic standard FNAB, and 4 with a palpable nodule. US-guided FNAB was nondiagnostic in 15 (23%) patients. There were no false-positive or false-negative results. Standard FNAB was performed in 407 patients, 57 (14%) of whom had a nondiagnostic result. There were 2 (3%) false-positive and 3 (1.6%) false-negative results. In 14 patients with a nondiagnostic standard FNAB, US-guided FNAB yielded an adequate specimen in 7 (50%). Nodules evaluated by standard FNAB were 4.1 +/- 0.1 cm (mean +/- SEM) in size compared with 2.5 +/- 0.1 cm for nodules evaluated by US-guided FNAB (P <.05). CONCLUSIONS: US improves the diagnostic yield in selected patients with nondiagnostic standard FNAB. The higher frequency of nondiagnostic US-guided FNAB was related to its selective use in patients with smaller nodules.     

Recommendations for the management of cystic thyroid nodules

BACKGROUND: The management of cystic thyroid nodules has not been standardized with respect to an initial fine-needle aspiration cytology (FNAC) cystic change result, which is defined as fluid aspiration and a smear with numerous macrophages but scant or no follicular cells. In the present study the physical characteristics of cystic thyroid nodules predictive of the pathology were investigated, and recommendations made on their management. METHODS: The aspiration results of 1436 thyroid nodules managed between 1998 and 2000 were investigated. A total of 157 patients who had a subsequent operation or follow-up data with reaspiration were the subjects of the present study. Age, sex, nodule characteristics and others were examined as possible predictors of cancer risk. RESULTS: The malignancy rate was 8.9%. Ten cases (71%) of malignancy were not cytologically diagnosed. Male sex and a nodule size of > or = 4 cm were found to be statistically significant predictors of malignancy. The malignancy rate was highest (100%) when a cystic lesion had malignant cytology on reaspiration and local invasion on radiology. CONCLUSIONS: When a cystic change is observed by initial FNAC of thyroid nodules, nodules of > or = 4 cm must be reaspirated and a firm cytologic diagnosis made to rule out malignancy. Nodules should be considered for surgery having taken into account other characteristics, in particular male sex and radiologic findings of local invasion.     

Pathologic nature of cystic thyroid nodules selected for surgery by needle aspiration biopsy

Sixty euthyroid patients with cystic hypofunctioning thyroid nodules were selected for operation by the criteria of evidence of needle aspiration of cyst fluid with malignant cytologic findings, suspicion of malignancy on the basis of recurrent cyst fluid formation after at least two aspirations, or incomplete decompression after aspiration. Other factors such as size (greater than 3 cm in diameter), history of radiation, and cervical lymphadenopathy were given weight. Radiation exposure occurred in 14% of patients. Surgical pathologic findings revealed malignancy in 32%, adenoma in 43%, and colloid nodule in 25%, with a total neoplasia rate of 75%. The types of malignant tumors included six papillary, six mixed, three follicular, and four Hurthle. Surgical treatment included 26 near total thyroidectomies, 34 partial thyroidectomies, and four neck dissections without major morbidity or deaths. Cytologic false-negative rates were 50% cancer, 50% Hurthle cell 50%, and 60% adenoma, even after nucleopore filtration, emphasizing the value of surgical selection on the basis of cyst response to aspiration. Cytologic false-positive rate in the colloid group was 6% and 25% for false (solid) positive for echography. Bloody fluid occurred in all types of lesions but was more common in the cancer group. Thyroid ultrasonography does not appear to be an important way to assess thyroid nodular disease and has been, in our estimation, superseded by needle aspiration cytology. It should be recognized that cystic thyroid nodules, when selected for operation on the basis of the above mentioned needle biopsy and clinical criteria, have the same frequency of neoplasia and cancer as solid hypofunctioning thyroid nodules. Hence, it is recommended that all cystic lesions of the thyroid gland be assessed in accordance with such criteria to exclude underlying cancer.     

Ultrasound-guided fine-needle aspiration and thyroid disease

BACKGROUND: Fine-needle aspiration represents a critical diagnostic test in determining proper management of thyroid disease and the use of ultrasound-guided fine-needle aspiration (USGFNA) has increased over the years. METHODS: A retrospective chart review of patients undergoing USGFNA. Two hundred fifteen patients underwent 234 procedures with 362 nodules aspirated within a 2 (1/2)-year period. RESULTS: The mean ages of women and men were 51.9 and 57.8, respectively. The average size of nodules was 2.1 cm. A difficult to assess gland or nodule was the most common indication for USGFNA (33%). The sensitivity was 88.2%, specificity was 80.0%, the PPV was 65.2%, the negative predictive value was 94.1%, and the accuracy was 82.5%. The cancer yield, inadequacy, and complication rates were 44%, 10.5%, and 8.5%, respectively. CONCLUSIONS: USGFNA aspiration is a safe and effective diagnostic modality in the management of thyroid disease, especially for nodules that are difficult to palpate.     

Management implications from routine needle biopsy of hyperfunctioning thyroid nodules

To evaluate the diagnostic and treatment consequences of using a routine needle biopsy procedure on all thyroid nodules without a radioisotopic scintigraphic study, 12 patients with documented hyperfunctioning thyroid nodules were retrospectively evaluated regarding the physical and cytologic observations obtained after a fine-needle (22 to 27-gauge) aspiration biopsy (FNB) procedure. Among the seven solid lesions, features of marked cellularity and nuclear pleomorphism were present in three and moderate sheets of epithelium in four raising the suspicion of underlying malignancy, while five mixed (cystic and solid) lesions were larger than 3 cm, hemorrhagic, and recurrent, with two having detectable sheets of epithelium. Evidence for concomitant lymphocytic thyroiditis was seen in five of 12 (42%) patients, and nine had positive serum antithyroid antibody titers as well. In conclusion, total reliance on FNB without scintigraphy could lead to operations on hyperfunctioning thyroid adenomas for suspected malignancy, of whom the vast majority would be benign, and could expose some unprepared patients with thyrotoxicosis to surgical morbidity. Routine thyroid hormone suppression therapy for apparently benign inflammatory or cystic degenerative lesions could also induce hyperthyroidism in patients with hyperfunctional or autonomous (nonsuppressible) nodules. When using an initial FNB approach, the need for thyroid function studies and scintigraphy before undertaking surgery or thyroid hormone feeding, as well as the consequences of omitting such studies, should be considered.     

Diagnostic imaging techniques in thyroid cancer

With the refinement of fine-needle aspiration, the specific applications of thyroid imaging techniques need to be reevaluated for efficiency and cost containment. No thyroid imaging test should be routinely obtained. Radionuclide scanning is most beneficial in evaluating the functional status of thyroid nodules when fine-needle aspiration is inadequate, the findings are benign, or when there is no discrete nodule that is palpated in an enlarged gland. When fine-needle aspiration is unavailable or unreliable, radionuclide scanning becomes a first-line diagnostic tool. Ultrasonography should be used primarily for identifying a solid component of a cystic nodule, determining the size of nodules on thyroxine suppression that are not easily palpable, or for performing guided fine-needle aspiration. Computerized tomography and magnetic resonance imaging both have a definite role in the evaluation of thyroid tumors. Magnetic resonance imaging is superior to computerized tomography for the evaluation of metastatic, retrotracheal, or mediastinal involvement of large thyroid tumors or goiters. Careful selection of the diagnostic techniques will ensure more accurate diagnosis and reduce unnecessary patient costs in the treatment of thyroid cancer.     

Is patient age associated with risk of malignancy in a ≥4 cm cytologically benign thyroid nodule?

BackgroundCurrent data regarding the risk of malignancy in a large thyroid nodule with benign fine-needle aspiration biopsy(FNAB) is conflicting. We investigated the impact of patient age on the risk of malignancy in nodules≥4 cm with benign cytology.MethodsWe performed a single-institution retrospective review of patients who underwent surgery from 07/2008–08/2019 for a cytologically benign thyroid nodule ≥4 cm. The relationship between malignant histopathology and patient and ultrasound features was assessed with multivariable logistic regression.ResultsOf 474 nodules identified, 25(5.3%) were malignant on final pathology. In patients <55 years old, 21/273(7.7%) nodules were malignant, compared to 4/201(2.0%) in patients ≥55. Patient age ≥55 was independently associated with significantly lower risk of malignancy(OR:0.2,95%CI:0.1–0.7,p = 0.011). Increasing nodule size >4 cm and high-risk ultrasound features were not associated with risk of malignancy(OR:1.0,95%CI:0.7–1.4,p = 0.980, and OR:9.6,95%CI:0.9–107.8,p = 0.066, respectively).ConclusionsPatients <55 years old are 3.7-fold more likely to have a falsely benign FNA biopsy in a nodule≥4 cm.     

Intraoperative decision making during thyroid surgery based on the results of preoperative needle biopsy and frozen section

Prognostic factors in well-differentiated thyroid cancer are age of the patient and grade, size, distant metastasis, and extracapsular spread of the disease. However, the surgeon is often not sure about the pathologic diagnosis of thyroid nodules. The accuracy of preoperative studies, such as ultrasonography and thyroid scanning, is limited. The most cost-effective test is fine-needle aspiration, the accuracy of which exceeds 80% in most series. However, a large group of nodules exist for which aspiration cytologic studies are considered to be either suspicious or indeterminate. The decision about the extent of thyroidectomy may be difficult in these patients. Intraoperative frozen section may help the surgeon to distinguish benign from malignant lesions, but as in fine-needle aspiration, the major problem is the distinction between follicular adenoma and follicular carcinoma. The frozen section diagnosis of follicular adenoma was changed to follicular carcinoma in one third of the cases (13 of 38 cases). The decision about the extent of thyroidectomy in patients with follicular adenomas was based on other prognostic factors, such as age and sex of the patient and the size of the nodule. The accuracy of frozen section diagnosis was 95%. Our experience suggests that decisions regarding the extent of thyroidectomy can best be made by preoperative fine-needle aspiration with confirmation by frozen section diagnosis in equivocal cases.     

The effects of fine-needle biopsy on thyroid hormone levels

OBJECTIVE: Our study aim was to investigate the effects of fine-needle biopsy used for thyroid nodules on serum thyroid hormone levels. STUDY DESIGN: A total of 25 patients who had solid nodules of the thyroid gland and normal thyroid hormone levels underwent diagnostic fine-needle biopsy for a nodule of the thyroid gland. METHODS: Venous blood samples were drawn from the cases for measurement of serum total T(3) and T(4), free T(3) and T(4), thyroid-stimulating hormone, and thyroglobulin levels before, immediately after, and 30 minutes after the initial biopsy. RESULTS: Total T(3) and thyroglobulin levels were found to be significantly higher immediately and 30 minutes following fine-needle aspiration biopsy, compared to the baseline levels (P<0.05). CONCLUSION: Preliminary data suggest that thyroid hormone levels show a mean increase of about 20% immediately after fine-needle aspiration. SIGNIFICANCE: The implication of this finding on patient care should be determined on an individual basis.     

The role of fine-needle aspiration in the diagnosis of thyroid nodules

The aim of this study was to prospectively evaluate the sensitivity, specificity and accuracy of fine-needle aspiration of thyroid nodules. From January 1978 to December 2003, 497 patients underwent fine-needle aspiration of thyroid nodules and then thyroidectomy. Fine-needle aspiration was performed with a fine 23-25 gauge and the aspirate was fixed and dyed with May-Grounwald-Giemsa method. The results of cytology were divided into four groups: positive for malignancy (77 patients), negative for malignancy (370 patients), suspect for malignancy (34 patients) and not diagnostic (16 patients). Suspect specimens also included follicular neoplasm and Hürthle cell neoplasm. Fine-needle aspiration results were compared with histopathologic analysis after thyroidectomy. There were 2 false-positive (0.5%) and 5 false-negative patients (1%). Sensitivity, specificity and accuracy were respectively 94.7%, 99% and 98.4%. This study confirms that fine-needle aspiration of thyroid nodules can be performed easily with high sensitivity, specificity and accuracy.     

Sex variability of fine-needle aspiration reliability in the diagnosis of malignancy in thyroid nodules ≥4 cm

Background

The effect of sex on fine-needle aspiration (FNA) diagnosis of thyroid cancer remains unknown. This study determines the reliability of FNA when evaluating thyroid nodules ≥4 cm in women and men.

Methods

Prospectively collected data of 1,068 patients who underwent FNA and thyroidectomy at a tertiary medical center were retrospectively reviewed. Data were stratified by sex and thyroid nodule size ≥4 cm.

Results

The FNA false-negative rate for thyroid malignancy in women and men was 17% and 0%, respectively. FNA was less predictive of malignancy in women (odd ratio = 31.7; 95% confidence interval, 19.2 to 52.5; P < .0001) compared with men (odds ratio = 51.7; 95% confidence interval, 11.8 to 225.1; P < .0001) with thyroid nodules ≥4 cm.

Conclusions

For the diagnosis of malignancy in large thyroid nodules, FNA may be less reliable in women compared with men. This study advocates using a more aggressive approach that includes surgical resection for definitive diagnosis in women with thyroid nodules ≥4 cm.     

Fine-needle aspiration biopsy specimen with a predominance of Hürthle cells: a dilemma in the management of nodular thyroid disease

BACKGROUND: A fine-needle aspiration biopsy (FNAB) specimen of a thyroid nodule with a predominance of Hürthle cells usually is indicative of a Hürthle cell neoplasm, but it also may occur with nonneoplastic disease. METHODS: A prospective nodular thyroid disease database was used to identify patients with a FNAB specimen consisting of a predominance of Hürthle cells. Clinical factors were investigated and FNAB specimens were examined in a blinded fashion by a single cytopathologist to determine if there were specific factors that could be used to distinguish nonneoplastic from neoplastic disease. RESULTS: Of the 738 patients with nodular thyroid disease, 622 had a FNAB specimen. The FNAB specimen was interpreted as consistent with a Hürthle cell neoplasm in 45 (7%) patients, 7 (16%) with carcinoma, 21 (47%) with adenoma, 12 (27%) with adenomatous hyperplasia, and 5 (11%) with thyroiditis. Extensive cellularity and absent colloid were associated with neoplastic disease (P < .05). No cytologic feature reliably excluded neoplastic disease (P > .05). No significant differences in age (x +/- SD) (51 +/- 17 vs 54 +/- 17 y), sex (female/male ratio, 6/1 vs 15/2), nodule size (3.9 +/- 1.9 vs 3.4 +/- 2.0 cm), weight of excised thyroid tissue (42 +/- 27 vs 33 +/- 30 g), or functional status of the thyroid gland was observed between patients with neoplastic (n = 28, 62%) versus nonneoplastic (n = 17, 38%) disease. CONCLUSIONS: Neoplastic disease accounts for two thirds of the pathology in patients with a predominance of Hürthle cells on FNAB specimen and neither clinical nor cytologic features reliably exclude Hürthle cell adenoma or carcinoma. As a result, thyroidectomy is recommended for all patients with a thyroid nodule and a predominance of Hürthle cells on FNAB specimen.     

超声引导下细针穿刺抽吸活检诊断甲状腺结节

目的探讨超声引导下细针穿刺抽吸活检(US-FNAB)对不同大小甲状腺结节的诊断价值。方法回顾分析在我院接受US-FNAB检查的689例患者736个甲状腺结节,超声测量结节最大径,并将其分为<5mm、5～10mm、>10mm组;对结节US-FNAB细胞学诊断结果与术后病理结果或随访结果进行比较,分析组间差异。结果 736个结节中,细胞学诊断恶性132个,可疑恶性61个,良性476个,不满意44个,不确定23个。经术后病理或临床随访,恶性结节208个,良性结节528个。恶性结节最大径小于良性结节(P<0.001)。5～10mm组结节的细胞学阳性率和实际恶性率均大于<5mm组及>10mm组(P均<0.05)。US-FNAB细胞学诊断甲状腺良恶性结节的敏感度为87.02%(181/208),特异度97.73%(516/528),准确率94.70%(697/736)。不同大小甲状腺结节US-FNAB检查的诊断敏感度、特异度、阳性预测值、阴性预测值及准确率差异均无统计学意义(P均>0.05)。结论 US-FNAB是判断甲状腺结节性质的有效手段,对不同大小结节都有较高诊断价值。     

Nodular thyroid disease in children and adolescents

Thyroid nodules in children are extremely uncommon. Most thyroid nodules, both benign and malignant, present as asymptomatic neck masses. A thyroid nodule in a child is significant because of the risk of malignancy. A review of medical records at our institution demonstrated 71 patients 20 years of age and younger with surgically managed thyroid nodules, of which 45 were benign and 26 were malignant. Our diagnostic workup, including serum thyroid studies, radiologic evaluation, and fine-needle aspiration, is discussed. Because of the possibility of malignancy, we recommend that all solitary thyroid nodules be excised in children unless fine-needle aspiration definitively determines a benign histology. The extent and type of surgical management is controversial and is still subject to much debate. Partial thyroidectomy appears adequate for benign disease, but even though there is no statistical difference in survival, we recommend total thyroidectomy for the management of malignant disease. (Otolaryngol Head Neck Surg 1996;116:604-9.)     

Isthmectomy: A Conservative Operation for Solitary Nodule of the Thyroid Isthmus

Purpose : To assess the results obtained in patients with nontoxic uninodular goiter confined to the isthmus undergoing isthmectomy.

Methods : Between April 1994 and June 2006, 330 consecutive patients with nontoxic uninodular goiter underwent thyroidectomy at our institution. In 31 patients, lesions were limited to the thyroid isthmus with evidence of benign or undetermined pathology on ultrasound-guided fine-needle aspiration biopsy. Total isthmectomy was performed. Results : Preoperatively, thyroid nodules on ultrasonography were solid in 26 patients and mixed with cystic and solid components in 2. The mean size of nodules was 2.43 (± 0.88) cm. No intraoperative or postoperative complications occurred. Histological examination showed nodular hyperplasia in 29 cases, follicular adenoma in 1 and papillary thyroid carcinoma in 1. The patient with papillary carcinoma underwent bilateral lobectomy 7 days later. A total of 24 patients (77.4%) attended clinical visits at follow-up (mean 70, 57 months). Ultrasonographic scanning revealed thyroid nodules in 17 patients, in 16 of which nodules range from one to five (0.5 to 2 cm in size) and further surgery was not indicated. One patient with a 4-cm nodule and tracheal displacement found at ultrasonography 2 years after isthmectomy had inconclusive results of FNAB. This patient was re-operated for completion thyroidectomy, which was successfully performed without technical difficulties. The detection of recurrent nodules was independent of the time elapsed since thyroid isthmectomy.

Conclusions : These findings document the feasibility and efficacy of isthmectomy in solitary thyroid nodules confined to the isthmus.     

Role Of Ultrasonography in Predicting Malignancy in Patients with Thyroid Nodules

The use of ultrasonography (USG) has become an essential part of endocrine surgical practice. We evaluated the value of USG in predicting malignancy of thyroid nodules. The accuracy of USG in 857 patients who underwent fine-needle aspiration (FNA) with or without surgery was analyzed in a prospective setting. The diagnostic accuracy of USG was compared to that of FNA and of combined models in 153 operated patients. The malignancy-predicting value of USG in follicular neoplasms and its relation to nodule size were also investigated. Sensitivity, specificity, and overall accuracy (OA) of USG were 84.9%, 95.5%, and 93.7%, respectively. In operated patients, USG had accuracy comparable to that of FNA and combined models (sensitivity 93.3%, specificity 90.6%, OA 92.0%) regardless of nodule size but showed a significant rate of indeterminate results (29.4%). For follicular neoplasms, the sensitivity, specificity, and OA of USG were 100%, 95.4%, and 96.1%, respectively, with indeterminate results for three malignant nodules (42.8%). This acceptable malignancy-predicting value of USG in thyroid nodules supports the potential role of USG for predicting malignancy in selected patients with thyroid nodules. However, the high rate of indeterminate results precludes it from being a standard independent diagnostic method for the present time. Part of this paper is presented as a poster at the 88th annual meeting of the Endocrine Society, June 24–27, Boston, MA, USA.     

Current management of the patient with autonomously functioning nodular goiter

Autonomously functioning thyroid nodules (AFTNs) are presumably independent of TSH for growth and function and appear "hot" on scintiscan because they selectively concentrate radionuclide to a greater extent than the remaining thyroid gland, which is controlled by the normal TH-TSH feedback mechanism. Such autonomously functioning tissue may occur in "patchy" areas, as a solitary nodule, or as multiple nodules (classic Plummer's disease), with the mass of hyperfunctioning tissue and the related secretion of thyroid hormones determining whether the patient is euthyroid or hyperthyroid. Important diagnostic tests include a 99mTc thyroid scan, T4 RIA, T3 uptake, FTI, TSH RIA, and occasionally T3 RIA ("T3 thyrotoxicosis"). Solitary autonomous nodules in adult patients characteristically progress slowly over many years, with toxicity rarely developing in nodules less than 2.5 cm in diameter and occurring primarily in nodules 3 cm or larger and in older patients. The decision to treat a solitary nodule depends upon the size and degree of function of the nodule and the patient's age. Surgery and radioactive iodine are effective therapies. Hyperfunctioning thyroid nodules in children and adolescents (under age 18) have a more rapidly progressive course than those in adults and should be treated by thyroid lobectomy at the time of diagnosis. Subtotal thyroidectomy is the preferred treatment for most patients with toxic multinodular goiter, because it achieves prompt control of the hyperthyroidism and removes the goiter. Radioiodine therapy and long-term antithyroid drug therapy are alternative forms of treatment for patients who are poor surgical risks or who develop recurrent hyperthyroidism following thyroid surgery.     

Evaluation and management of incidental thyroid nodules in patients with another primary malignancy

BACKGROUND: Studies indicate that incidentally discovered thyroid nodules >or=1 cm in size may have a higher rate of malignancy (7% to 29%) than traditionally discovered nodules (5%). We sought to determine the rate of malignancy in incidental thyroid nodules in patients with other malignancies, and examine the accuracy of ultrasound (US) versus computed tomography (CT) in determining nodule size. METHODS: We evaluated 41 patients with history of another known malignancy (gastrointestinal, 23; breast, 11; other, 7) referred with an incidental thyroid nodule. Patients underwent office-based US and biopsy of nodules >or=1 cm. Surgical intervention was based on biopsy results. We compared nodule size at pathology with size seen on CT or US. RESULTS: Thirty-five patients met criteria for biopsy. Of the 35, 20 (57%) had atypical biopsy results warranting resection. Sixteen of those 20 underwent surgery. Pathology yielded 4 papillary thyroid cancers (PTC), 4 microPTC, 2 metastatic cancers, and 7 benign lesions. Ultrasound measurement of nodules compared to size measured at pathology had an r2 correlation value of 0.90 with P value <.0001. CT scan had an r2 value of 0.83 and P value of .005. CONCLUSIONS: Incidental thyroid nodules in patients with another primary malignancy warranted resection in 57%. The rate of malignancy in incidental thyroid nodules was 24%, which is above the expected rate of 5% seen in traditionally discovered nodules. US correlation with nodule size at pathology was excellent and superior to CT scan. Incidentally discovered thyroid nodules >or=1 cm, seen in patients with another malignancy, warrant further evaluation.     

Diagnostic accuracy of fine-needle aspiration biopsy versus frozen section in solitary thyroid nodules

Fine-needle aspiration biopsy is widely used in the diagnosis and management of the solitary thyroid nodule. It is the most accurate tool available and decreases the need for ultrasonography and thyroid scanning. In those patients who are selected for surgical treatment by fine-needle aspiration biopsy, it has been advocated as a guide to determining the extent of operation. Frozen section, which usually serves as the surgeon's guide, and fine-needle aspiration biopsy both have varying accuracy rates. Few direct comparisons have been made. We studied 198 aspirates in 198 patients who presented with a solitary nodule and had surgical excision. Fine-needle aspiration biopsy (198 cases) and frozen section (182 cases) were compared with the final histologic diagnosis. Accuracy rates for fine-needle aspiration biopsy and frozen section were 90 percent and 95 percent, respectively. Fine-needle aspiration biopsy detected 43 percent of the cancers and frozen section, 64 percent. There were no false-positive diagnoses with frozen section, but three cases with fine-needle aspiration biopsy. The false-negative diagnosis rate was 5 percent for frozen section and 8.5 percent for fine-needle aspiration biopsy. When the "other" diagnosis category was grouped with the "positive" diagnosis category and a single expert cytopathologist was used to read the cytology report, the sensitivity was increased to 80 percent whereas the accuracy was maintained at 83 percent. We believe that since there were no false-positive diagnosis using frozen section, it can reliably be used as a guide when it reveals malignancy. When the fine-needle aspiration biopsy diagnosis is "positive" or "other," it can guide operation, but only after carefully assessing the wording of the cytology report and the clinical situation. Each modality can provide information missed by the other. We continue to use them as complementary tools in the diagnosis and management of solitary thyroid nodules.