The utility of frozen section evaluation for follicular thyroid lesions

Incidental but Not Insignificant: Thyroid Cancer in Patients with Graves Disease

BACKGROUND

Graves disease is the most common cause of hyperthyroidism in the US. Treatment with antithyroid drugs and radioactive iodine is more commonly used than surgical management with total thyroidectomy (TTx). However, incidentally discovered thyroid cancer (TC) has been described on surgical pathology from patients who underwent surgical treatment of Graves disease, which would be missed with these other treatment strategies. We sought to determine the incidence rate of TC among patients with surgically treated Graves disease.

STUDY DESIGN

We retrospectively reviewed patients with Graves disease who underwent TTx at a single institution from 2011 to 2023. Pathology reports were reviewed for TC. Patient demographics, preoperative laboratory and radiological evaluations, preoperative medical management, and surgical outcomes were compared between patients with and without incidental TC.

RESULTS

There were 934 patients, of whom 60 (6.4%) patients had incidentally discovered TC on pathology. The majority (58.3%) of patients had papillary thyroid carcinoma, followed by 33.3% with papillary microcarcinoma. Preoperative ultrasound (US) was obtained in 564 (60.4%) of patients, with 44.3% with nodules, but only 34 (13.7%) of those with nodules had TC on final pathology. Preoperative fine needle aspiration was obtained in 15 patients with TC, and 8 patients (53.3%) were reported as benign lesions, which ultimately had TC on final pathology. There was no difference in sex, race or ethnicity, preoperative medical management, and postoperative outcomes between the 2 groups.

CONCLUSIONS

Incidental TC was found on surgical pathology in 6.4% of patients undergoing TTx for Graves disease. Preoperative imaging with US and fine needle aspiration were often unreliable at predicting TC. The incidence of TC should not be underestimated when counseling patients on definitive management for Graves disease.

Can a Multidisciplinary Endocrine Clinic be Beneficial for Patients and Surgeons?

BACKGROUND

Multidisciplinary clinics are expected to improve patient care by enhancing efficiency for both patients and care providers. We hypothesized that while these clinics are an efficient use of time for patients, they can limit a surgeon's productivity.

METHODS

A retrospective review was performed for patients evaluated in a Multidisciplinary Endocrine Tumor Clinic (MDETC) and Multidisciplinary Thyroid Cancer Clinic (MDTCC) from 2018 to 2021. Time from evaluation to surgery and prevalence of surgery were evaluated. Patients were compared to those evaluated in a surgeon-only endocrine surgery clinic (ESC) from 2017 to 2021. Chi-square and t-tests were used to test significance.

RESULTS

Patients referred to the ESC underwent surgery more often than those referred to either multidisciplinary clinic (ESC 79.5%, MDETC 24.6%, MDTCC 7%; P < .001) but had a significantly longer delay between appointment and operation (ESC 19.9 days, MDETC 3.3 days, MDTCC 16.4 days; P < .001). Patients had a longer wait from referral to appointment for the MDCs (ESC 22.6 days, MDETC: 44.5, MDTCC 33; P < .05). There was no significant difference in miles traveled by patients to any clinic.

CONCLUSION

Multidisciplinary clinics can provide fewer appointments and faster time to surgery for patients but may lead to longer wait time from referral to appointment and fewer overall surgeries than endocrine surgeon-only clinics.

Rapid diagnosis of papillary thyroid carcinoma with machine learning and probe electrospray ionization mass spectrometry

Frozen section examination could provide pathological diagnosis for surgery of thyroid nodules, which is time-consuming, skill- and experience-dependent. This study developed a rapid classification method for thyroid nodules and machine learning. Total 69 tissues were collected including 43 nodules and 26 nodule-adjacent tissues. Intraoperative frozen section was first performed to give accurate diagnosis, and the rest frozen specimen were pretreated for probe electrospray ionization mass measurement. By multivariate analysis of mass scan data, a series compounds were found downregulated in the extraction solution of papillary thyroid carcinoma (PTC), but some were found upregulated by mass spectrometry imaging. m/z 758.5713 ([PC[34:2] + H]⁺ ), m/z 772.5845 ([PC[32:0] + K]⁺ ), and m/z 786.6037 ([PC[36:2] + H]⁺ ) were firstly identified as potential biomarkers for nodular goiter (NG). Machine learning was employed by means of support vector machine (SVM) and random forest (RF) algorithms. For classification of PTC from NG, SVM and RF algorithms exhibited the same performance and the concordance was 94.2% and 94.4% between prediction and pathological diagnosis with positive and negative mass dataset, respectively. For the classification of PTC from PTC adjacent tissues, SVM was better than RF and the concordance was 93.8% and 83.3% with positive and negative mass dataset, respectively. With the identified compounds as training features, the sensitivity and specificity are 87.5% and 88.9% for the test set. The developed method could also correctly predict the malignancy of one medullary thyroid carcinoma and one adenomatous goiter (benign). The diagnosis time is about 10 min for one specimen, and it is very promising for the intraoperative diagnosis of papillary thyroid carcinoma.

Prophylactic Central Neck Dissection in Papillary Thyroid Carcinoma: All Risks, No Reward

BACKGROUND

Central neck dissection (CND) remains a controversial intervention for papillary thyroid carcinoma (PTC) patients with clinically negative nodes (cN0) in the central compartment. Proponents state that CND in cN0 patients prevents locoregional recurrence, while opponents deem that the risks of complications outweigh any potential benefit. Thus, there remains conflicting results amongst studies assessing oncologic and surgical outcomes in cN0 PTC patients who undergo CND. To provide clarity to this controversy, we sought to evaluate the efficacy, safety, and oncologic impact of CND in cN0 PTC patients at our institution.

MATERIALS AND METHODS

Six hundred and ninety-five patients with PTC who underwent thyroidectomy at our institution between 1998 and 2018 were identified using an institutional cancer registry and supplemental electronic medical record queries. Patients were stratified by whether or not they underwent CND; identified as CND(+) or CND(-), respectively. Patients were also stratified by whether or not they received adjuvant radioactive iodine (RAI) therapy. Patient demographics, pathologic results, as well as surgical and oncologic outcomes were reviewed. Standard statistical analyses were performed using ANOVA and/or t-test and chi-squared tests as appropriate.

RESULTS

Among the 695 patients with PTC, 492 (70.8%) had clinically and radiographically node negative disease (cN0). The mean age was 50 ± 1 years old and 368 (74.8%) were female. Of those with cN0 PTC, 61 patients (12.4%) underwent CND. CND(+) patients were found to have higher preoperative thyroid stimulating hormone (TSH) values, 2.8 ± 0.8 versus 1.5 ± 0.2 mU/L (P = 0.028) compared to CND(-) patients. CND did not significantly decrease disease recurrence, development of distant metastatic disease (P = 0.105) or persistence of disease (P = 0.069) at time of mean follow-up of 38 ± 3 months compared to CND(-) patients. However, surgical morbidity rates were significantly higher in CND(+) patients; including transient hypocalcemia (36.1% versus 14.4%; P < 0.001), transient recurrent laryngeal nerve (RLN) injury (19.7% vers us 7.0%; P < 0.001), and permanent RLN injury (3.3% versus 0.7%; P < 0.001).

CONCLUSIONS

The majority of patients at our institution with cN0 PTC did not undergo CND. This data suggests that CND was not associated with improvements in oncologic outcomes during the short-term follow-up period and led to increased postoperative morbidity. Therefore, we conclude that CND should not be routinely performed for patients with cN0 PTC.

A single institution experience with papillary thyroid cancer: Are outcomes better at comprehensive cancer centers?

INTRODUCTION

Papillary thyroid cancer (PTC) is the most common form of thyroid cancer. Although the survival rate is excellent, recurrence is as high as 20%. The mainstay of therapy is thyroidectomy and lymph node dissection based on risk factors. Data from other cancers suggest that surgical outcomes are most optimal at comprehensive cancer centers. We hypothesize that patients with PTC who had their initial operation at a comprehensive cancer center would have a better oncologic outcome.

METHODS

We utilized an IRB-approved cancer care registry database of patients with thyroid cancer who were seen at our institution between 2000 and 2018. Patient records were updated with cancer-specific outcomes including recurrence and need for re-intervention. Clinical and surgical outcomes were then compared between patients who had their initial operation at a comprehensive cancer center (CCC group, n = 503) versus those who did not (non-CCC group, n = 72).

RESULTS

Mean patient age was 49 ± 16 years and 70% were female. Average tumor size was 1.6 ± 1.6 cm. There was no difference in tumor size, age, gender or race between groups. Pre-operative ultrasound was more frequently performed at the CCC (89%) than at non-CCC's (51%, p < 0.001). CCC patients were more likely to undergo initial total thyroidectomies compared to non-CCC patients (76% vs. 21%, p < 0.001). Positive surgical margins were more frequently found in patients at non-CCC's (19%) than at the CCC (9.7%, p = 0.016). Finally, CCC patients had a significantly lower cancer recurrence rate (5.0% vs. 37.5%, p < 0.001). Therefore, the need for additional cancer operations was much greater in patients who had initial thyroid surgery at non-CCC (31.9% vs. 1.4%, p < 0.001).

CONCLUSIONS

Patients with PTC who have their initial thyroidectomy at non-CCC have higher recurrence rates, higher rates of positive tumor margins on pathology, and increased need for additional operations. These data suggest that patients who have their initial procedure at a CCC for PTC have better long-term outcomes.

Intraoperative parathyroid hormone measurement facilitates outpatient thyroidectomy in children

INTRODUCTION

We hypothesize that intraoperative parathyroid hormone (ioPTH) measurement after a total thyroidectomy predicts children at risk for hypoparathyroidism and allow for outpatient procedure.

METHODS

Between 2015 and 2019, we reviewed all patients under the age of 21 undergoing a thyroidectomy (total or lobectomy). Based on the ioPTH concentration, the patients were treated by the following protocol: a) PTH ≥20 pg/mL: no treatment; b) PTH = 10-19 pg/mL: 1000 mg calcium orally TID; c) PTH = 5-9 pg/mL: calcitriol 250 μg orally BID plus 1000 mg calcium orally TID; or d) PTH <5 pg/mL calcitriol 500 μg orally BID plus 1000 mg calcium orally TID.

RESULTS

Fifty-two patients were included with a median age of 16 (range 6-21 years). Thirty-two patients (62%) had normal PTH (≥10 pg/mL) while 20 (38%) had low PTH levels (<10 pg/mL). Of those patients with low PTH, 60% had normalization of levels within 2 weeks of surgery.

CONCLUSIONS

Thyroid surgery in children can be performed as an outpatient procedure. The ioPTH measurements and a protocol to treat patients with low PTH assists in safe discharge.

Cost effectiveness of intraoperative pathology in the management of indeterminate thyroid nodules

Objective This study aims to determine the cost effectiveness of rapid frozen section (RFS) for indeterminate thyroid nodules. Materials and methods A retrospective chart review was conducted between January 2009 and June 2013 at a tertiary care institution. Main outcomes were number needed to treat, RFS efficacy, and cost-savings of avoiding second completion thyroidectomy. Cost-effectiveness was estimated using 2015 Medicare reimbursement rate. Results Out of 1,114 patients undergoing thyroid surgery, 314 had preoperative AUS/FLUS cytopathology and subsequent thyroid lobectomy with RFS. RFS identified 13 of the 32 patients with malignancy resulting in a total thyroidectomy. 19 of the 29 malignancies not detected by RFS were papillary microcarcinomas. Conclusions Completion thyroidectomy was avoided in 1 out of every 24 patients resulting in cost-savings of $ 80.04 per patient. In the era of outpatient thyroid surgery, intraoperative RFS for indeterminate thyroid nodules is cost-effective.

Application of machine learning to ultrasound images to differentiate follicular neoplasms of the thyroid gland

Purpose

This study was conducted to evaluate the diagnostic performance of machine learning in differentiating follicular adenoma from carcinoma using preoperative ultrasonography (US).

Methods

In this retrospective study, preoperative US images of 348 nodules from 340 patients were collected from two tertiary referral hospitals. Two experienced radiologists independently reviewed each image and categorized the nodules according to the 2015 American Thyroid Association guideline. Categorization of a nodule as highly suspicious was considered a positive diagnosis for malignancy. The nodules were manually segmented, and 96 radiomic features were extracted from each region of interest. Ten significant features were selected and used as final input variables in our in-house developed classifier models based on an artificial neural network (ANN) and support vector machine (SVM). The diagnostic performance of radiologists and both classifier models was calculated and compared.

Results

In total, 252 nodules from 245 patients were confirmed as follicular adenoma and 96 nodules from 95 patients were diagnosed as follicular carcinoma. As measures of diagnostic performance, the average sensitivity, specificity, and accuracy of the two experienced radiologists in discriminating follicular adenoma from carcinoma on preoperative US images were 24.0%, 84.0%, and 64.8%, respectively. The sensitivity, specificity, and accuracy of the ANN and SVM-based models were 32.3%, 90.1%, and 74.1% and 41.7%, 79.4%, and 69.0%, respectively. The kappa value of the two radiologists was 0.076, corresponding to slight agreement.

Conclusion

Machine learning-based classifier models may aid in discriminating follicular adenoma from carcinoma using preoperative US.

Utility of Intraoperative Frozen Section in Large Thyroid Nodules

OBJECTIVE

To determine if the routine use of intraoperative frozen section (iFS) results in cost savings among patients with nodules >4 cm with nonmalignant cytology undergoing a thyroid lobectomy.

STUDY DESIGN

Case series with chart review; cost minimization analysis.

SETTING

Single academic center.

SUBJECTS AND METHODS

Records were reviewed on a consecutive sample of 48 patients with thyroid nodules >4 cm and nonmalignant cytology who were undergoing thyroid lobectomy in which iFS was performed between 2010 and 2015. A decision tree model of thyroid lobectomy with iFS was created. Comparative parameters were obtained from the literature. A cost minimization analysis was performed comparing lobectomy with and without iFS and the need for completion thyroidectomy with costs estimated according to 2014 data from Medicare, the Bureau of Labor Statistics, and the Nationwide Inpatient Sample.

RESULTS

The overall malignancy rate was 25%, and 33% of these malignancies were identified intraoperatively. When the malignancy rates obtained from our cohort were applied, performing routine iFS was the less costly scenario, resulting in a savings of $486 per case. When the rate of malignancy identified on iFS was adjusted, obtaining iFS remained the less costly scenario as long as the rate of malignancies identified on iFS exceeded 12%. If patients with follicular lesions on cytology were excluded, 50% of malignancies were identified intraoperatively, resulting in a savings of $768 per case.

CONCLUSIONS

For patients with nodules >4 cm who are undergoing a diagnostic lobectomy, the routine use of iFS may result in decreased health care utilization. Additional cost savings could be obtained if iFS is avoided among patients with follicular lesions.

Economic Impact of Frozen Section for Thyroid Nodules with "Suspicious for Malignancy" Cytology

Objective To perform a cost analysis of the routine use of intraoperative frozen section (iFS) among patients undergoing a thyroid lobectomy with "suspicious for malignancy" (SUSP) cytology in the context of the 2015 American Thyroid Association guidelines. Study Design Case series with chart review; cost minimization analysis. Setting Academic. Subjects and Methods Records were reviewed for patients with SUSP cytology who underwent thyroid surgery between 2010 and 2015 in which iFS was utilized. The diagnostic test performance of iFS and the frequency of indicated completion/total thyroidectomies based on the 2015 guidelines were calculated. A cost minimization analysis was performed comparing lobectomy, with and without iFS, and the need for completion thyroidectomy according to costs estimated from 2014 data from Medicare, the Bureau of Labor Statistics, and the Nationwide Inpatient Sample. Results Sixty-five patients met inclusion criteria. The malignancy rate was 61.5%, 45% of which was identified intraoperatively. The specificity and positive predictive value were 100%. The negative predictive value and sensitivity were 83% and 95%, respectively. Completion/total thyroidectomy was indicated for 9% of patients; 83% of these individuals had findings on iFS that would have changed management intraoperatively. Application of the new guidelines would have resulted in a significant reduction in the frequency of conversion to a total thyroidectomy when compared with the actual management (26.1% vs 7.7%, P = .005). Performing routine iFS was the less costly scenario, resulting in a savings of $474 per case. Conclusion For patients with SUSP cytology undergoing lobectomy, routine use of iFS would result in decreased health care utilization.

Proof-of-concept Raman spectroscopy study aimed to differentiate thyroid follicular patterned lesions

Inter-observer variability and cancer over-diagnosis are emerging clinical problems, especially for follicular patterned thyroid lesions. This challenge strongly calls for a new clinical tool to reliably identify neoplastic lesions and to improve the efficiency of differentiation between benign and malignant neoplasms, especially considering the increased diagnosis of small carcinomas and the growing number of thyroid nodules. In this study, we employed a Raman spectroscopy (RS) microscope to investigate frozen thyroid tissues from fourteen patients with thyroid nodules. To generate tissue classification models, a supervised statistical analysis of the Raman spectra was performed. The results obtained demonstrate an accuracy of 78% for RS based diagnosis to discriminate between normal parenchyma and follicular patterned thyroid nodules, and 89% accuracy - for very challenging follicular lesions (carcinoma versus adenoma). RS translation into intraoperative diagnosis of frozen sections and in preoperative analysis of biopsies can be very helpful to reduce unnecessary surgery in patients with indeterminate cytological reports.

The futility of intraoperative frozen section in the evaluation of follicular thyroid lesions

OBJECTIVE

Investigate the utility of intraoperative frozen section (iFS) in patients with follicular thyroid lesions following publication of the 2015 American Thyroid Association (ATA) guidelines.

STUDY DESIGN

Retrospective chart review.

METHODS

Patient demographics, preoperative cytology, frozen pathology, and final pathology were reviewed on patients undergoing thyroid surgery at a tertiary care hospital in which iFS was utilized over a 5-year period. The test performance of iFS and the frequency of indicated completion/total thyroidectomies pre- and postpublication of the 2015 ATA guidelines were calculated.

RESULTS

One hundred and one patients met inclusion criteria: 54 patients with follicular lesions of undetermined significance (FLUS) and 47 patients with a cytologic diagnosis of suspicious for follicular neoplasm/follicular neoplasm. The malignancy rate was 36%, but only 14% of malignancies were identified on iFS. A definitive benign or malignant diagnosis was given on iFS in only 21% of cases, and operative management was altered in two cases as a result of iFS. There was a statistically significant reduction in the frequency of indicated total/completion thyroidectomies based on high-risk features as a result of the 2015 ATA guidelines compared to prior recommendations (20.8% vs. 5.0%, P = < 0.001). None of these patients had findings on iFS that would have altered management intraoperatively.

CONCLUSION

Intraoperative frozen section offers minimal diagnostic utility in the evaluation of follicular thyroid lesions. Updates in the 2015 ATA guidelines further diminish its potential to impact management intraoperatively. Significant improvements in its ability to identify malignancies would be needed to justify its use.

LEVEL OF EVIDENCE

4. Laryngoscope, 128:1501-1505, 2018.

Prediction Table and Nomogram as Tools for Diagnosis of Papillary Thyroid Carcinoma: Combined Analysis of Ultrasonography, Fine-Needle Aspiration Biopsy, and BRAF V600E Mutation

Although ultrasonography (US)-guided fine-needle aspiration biopsy (FNAB) is the most reliable diagnostic modality for evaluating thyroid nodules, 10% to 40% of FNAB samples yield indeterminate findings. The BRAF V600E mutation, a highly specific molecular marker for papillary thyroid carcinoma (PTC), well known for its prognostic value, has dubious diagnostic value because of its low sensitivity. Novel strategies are clearly needed to distinguish PTC, which represents the majority of thyroid malignancies, from other thyroid nodules. The records of 3297 patients with surgically proven PTC were retrospectively reviewed. A prediction table and nomogram were designed using a combination of diagnostic parameters for US, FNAB, and the BRAF V600E mutation. For the nomogram, parameters were proportionally assigned 0 to 100 points according to their regression coefficient for PTC. The probability of PTC for thyroid nodules with intermediate-risk (IR) US and atypia of undetermined significance/follicular lesion of undetermined significance (AUS/FLUS) FNAB was significantly dependent on BRAF V600E mutation status based on our prediction table (negative, 29.2% vs positive, 87.5%; P < 0.001). By our nomogram, the probability of PTC for thyroid nodules with IR US, AUS/FLUS FNAB, and positive BRAF V600E mutation was approximately 85% to 90%. We strongly recommend preoperative evaluation of the BRAF V600E mutation in indeterminate thyroid nodules. The prediction table and nomogram developed in this study could help clinicians and patients easily assess the probability of PTC in the preoperative period.

The Bethesda System for Reporting Thyroid Cytopathology is applicable to frozen section diagnosis in children

The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) offers standardized and widely understood diagnostic categories for reporting thyroid cytology diagnoses. We compared the utility of TBSRTC categories in pediatric cytology diagnoses and pediatric intraoperative frozen section diagnoses. We examined the experience of our primary and referral care center over a 20-year period. This included 182 thyroidectomy patients who underwent 64 preoperative fine-needle aspirations and 91 intraoperative frozen section evaluations, including 38 patients evaluated sequentially by each method. All diagnoses were retrospectively reclassified into TBSRTC categories and correlated with the final thyroidectomy diagnoses. For each sampling method, malignant final diagnoses were observed at similar frequencies to rates predicted by TBSRTC. Malignant final diagnoses following fine-needle aspiration or frozen section diagnoses in TBSRTC categories other than malignant or suspicious for malignancy most often resulted from difficulty in detecting papillary carcinoma, including difficulty detecting the nuclear characteristics of papillary carcinoma in frozen sections. The limitations of needle biopsy and frozen section evaluations differ, yet serial utilization of these procedures was rarely informative. Based on the experience of our institution, classification of cytology and frozen section diagnosis by TBSRTC predicts a risk of malignancy similar to the guidance offered by TBSRTC. We recommend including a TBSRTC category when reporting either thyroid cytology or frozen section diagnoses in children.

Better understanding in the differentiation of thyroid follicular adenoma, follicular carcinoma, and follicular variant of papillary carcinoma: a retrospective study

Background. To evaluate the role of ultrasonography (US), US-guided fine-needle aspiration (USFNA) and intraoperative frozen section (FS) in follicular neoplasm. Methods. US features, USFNA cytology, and FS results were compared based on the pathology results of patients with follicular adenoma (FA), follicular carcinoma (FC), and follicular variant of papillary thyroid carcinoma (FVPTC). Results. FC and FVPTC showed significantly higher rates of suspicious US features (P < 0.05) and positive findings on either US or cytology, 80.0% and 90.7%, compared to FA, 64.5% (P = 0.001). Intraoperative FS showed higher malignant rates in FVPTC and FC (81.8% and 75.0%, resp.), compared to FA (3.8%, P < 0.001). Conclusion. Suspicious US features were more significantly seen in FC and FVPTC compared to FA. Intraoperative FS is useful in the differential diagnosis of these lesions and supplements cytology results of USFNA.

Approach to the patient with nontoxic multinodular goiter

Thyroid nodules are very common, and although the majority are benign, approximately 5% may harbor malignancy. The evaluation of the patient with solitary thyroid nodule is generally straightforward and will typically include measurement of serum TSH to assess thyroid function and fine-needle aspiration biopsy of the nodule, with or without ultrasound (US) guidance. The approach to the patient with nontoxic multinodular goiter represents a more difficult problem for the clinician. All patients should have serum TSH measured to assess functional thyroid status and US examination to evaluate the number, size, and sonographic features of the nodules and assist in the selection of nodules that may need fine-needle aspiration biopsy. Patients with nodules yielding malignant cytology should be referred for surgery. Given the lack of reliable markers to predict biological behavior of nodules with suspicious (indeterminate) cytology, patients with such nodules are generally advised to have surgery, unless autonomous function of these nodules can be confirmed by scintigraphy. Most of these patients, however, will ultimately prove to have benign follicular tumors. Many patients with benign but large goiters may experience clinical symptoms of pressure, such as dysphagia, choking sensation, or airway obstruction. Such patients will often require surgery for alleviation of symptoms. In the absence of malignancy, asymptomatic patients may be observed. Radioactive iodine, commonly used in many parts of Europe, is safe and effective and may be a reasonable option for many patients. Periodic follow-up with neck palpation and US exam is recommended for all patients.

Operative Decision-Making for Follicular Thyroid Lesions: A Community Hospital System Experience

Follicular neoplasms of the thyroid are a frequent indication for surgery of the thyroid gland. We evaluated the use of frozen sections on intraoperative decision-making, possible avoidance of reoperative surgery, and histologic findings in a retrospective cohort. A database was created of all thyroid operations from 2001 to 2007. Data collected included age, gender, preoperative cytology, indication for surgery, surgeon, intraoperative decision-making, and histologic findings. Of the 723 thyroidectomies, 203 were performed for follicular neoplasms diagnosed by fine needle aspiration. Of these, 135 had cytology reports available within our electronic medical record; 44 per cent (59 of 135) of these patients had an intraoperative frozen section. Only two of 59 (3.4%) were positive for carcinoma, both of which were papillary carcinomas. One was interpreted as “suspicious” for carcinoma by the pathologist. In these three cases, the surgeon proceeded with total thyroidectomy at the time of initial surgery. The results of frozen section altered the operation in only three of 59 cases (5.1%). Intraoperative frozen section rarely impacts the conduct of thyroidectomy for follicular neoplasms.

Thyroid nodules; interpretation and importance of fine-needle aspiration (FNA) for the clinician - practical considerations

Thyroid nodules are very common lesions. Despite that the great majority is benign, in a significant percentage of them there is an underlying malignancy. Malignant thyroid nodules should be managed surgically, while the more common benign thyroid nodules may be managed conservatively. A systemic and careful diagnostic evaluation is needed to recognize nodules (overtly malignant or with malignant potential), and to avoid unnecessary surgery in a large percentage of patients with benign disease. Fine-needle aspiration (FNA) has a central role in the diagnostic investigation of the patient with thyroid nodules. FNA is a safe, useful, and cost-effective procedure. To increase accuracy, FNA can be performed under ultrasonographic guidance (if needed). Its results may be particularly helpful in determining the indication for surgery. In contrast, the role of FNA in selecting the extent of surgery is limited today. This is due to the fact that during the last decade there is a clear trend toward radical surgical management of thyroid nodular disease (both benign and malignant) by total/near-total thyroidectomy.

Thyroid follicular neoplasm: analysis by fine needle aspiration cytology, frozen section, and histopathology

We performed a retrospective analysis of follicular neoplasm data obtained from frozen section examinations of thyroid nodules. A total of 5,660 patients underwent preoperative neck ultrasonography and fine-needle aspiration cytology (FNAC), surgical treatment, and follow-up at a medical institute. Patients with papillary thyroid microcarcinoma were excluded from this study. In 971 cases, frozen section examination was performed during the surgical treatment of follicular neoplasm that was diagnosed via FNAC. Thyroid malignancies were histologically confirmed in 25.1% of cases (244/971). Among the patients with papillary thyroid carcinoma, 45 were diagnosed with the follicular variant of papillary thyroid carcinomas (27.4%). The diagnostic sensitivity of frozen section for the nonfollicular variant of papillary thyroid carcinoma was better than that for the follicular variant of papillary thyroid carcinoma (89.1% versus 78.9%; P = 0.1023). For 12 cases the diagnosis was atypical follicular adenomas. The diagnostic accuracy of frozen section in cases of follicular neoplasm was 76.9% with a sensitivity of 84.8% and a specificity of 98.9%. In conclusion, our analysis revealed high rates of accuracy when using frozen tissue sections for early diagnosis and treatment of follicular neoplasm; thus, an early decision to extent of surgery prevents a risky follow-up surgery.

How to approach thyroid nodules with indeterminate cytology

BACKGROUND

Ultrasound (US)-guided fine-needle aspiration biopsy (FNAB) is an accurate, reliable, and simple procedure to perform, and it is nowadays accepted as a standard diagnostic method for the differential diagnosis of thyroid nodules. However, a major limitation of US-FNAB is indeterminate cytology results at a thyroid nodule. This study investigated the clinical and US characteristics that predict malignancy, as well as the role of intraoperative frozen sections (FS) in the treatment of thyroid nodules with indeterminate cytology.

METHODS

From September 2002 to December 2007, the medical records of 181 patients (185 nodules) with indeterminate FNAB cytology results were retrospectively reviewed. Among them, 99 patients (M:F = 13:86; mean age, 43.71 years) with 99 thyroid nodules underwent subsequent surgery with pathologic confirmation. Seventy-eight patients (78.8%) underwent intraoperative FS. US findings of the surgically proven thyroid nodules were retrospectively reviewed. US features, clinical characteristics, and FS results were compared to the surgically proven pathologic results.

RESULTS

Nineteen nodules (19.2%) with indeterminate FNAB cytology were diagnosed as malignant. Lesion size varied from 4 to 70 mm (mean, 27.0 mm). Male patients (46.2%) were more significantly associated with malignancy than female patients (15.1%, P < 0.05). Microlobulated or ill-defined margins (87.5%), microcalcifications (50.0%), and taller-than-wide shape (80.0%) were US features showing correlations with malignancy (P < 0.05). Intraoperative FS significantly predicted malignancy (P < 0.05). Of the 78 cases with FS, 29 cases (37.2%) were deferred. Among the remaining 49 cases, 4 (5.1%) were malignant on FS and subsequent surgical pathology. Forty-five cases (57.7%) were diagnosed as benign on FS, but only two cases were diagnosed as malignant on surgical pathology.

CONCLUSIONS

Ultrasound is a feasible method in predicting malignancy in thyroid nodules with indeterminate FNAB cytology. Also, intraoperative FS is a supportive method with high specificity that may guide the treatment of thyroid nodule with indeterminate cytology.

A meta-analysis of comparing fine-needle aspiration and frozen section for evaluating thyroid nodules

The literature on comparing fine-needle aspiration (FNA) and frozen section for evaluating thyroid nodules was reviewed. Publications on this subject were divided into three groups (follicular lesions, non-follicular lesions and thyroid lesions, not otherwise specified). A meta-analysis was done to compare sensitivity, specificity, and positive and negative predictive values between FNA and frozen section diagnoses. For follicular lesions, FNA was much more sensitive but less specific, with lower positive predictive value than frozen section. FNA and frozen section are virtually identical in all parameters of accuracy in evaluating thyroid nodules that are not follicular lesions. The third group of publications that did not separate/specify follicular lesions from non-follicular lesions was non-contributory.

Molecular testing for mutations in improving the fine-needle aspiration diagnosis of thyroid nodules

CONTEXT

Thyroid nodules are common in adults, but only a small fraction of them are malignant. Fine-needle aspiration (FNA) with cytological evaluation is the most reliable tool for cancer diagnosis in thyroid nodules. However, 10-40% of nodules are diagnosed as indeterminate by cytology, making it difficult to optimally manage these patients.

OBJECTIVE

The aim of this study was to establish the feasibility and role of testing for tumor-specific mutations in improving the FNA diagnosis of thyroid nodules.

DESIGN

The prospective study included 470 FNA samples of thyroid nodules from 328 patients. At the time of aspiration, a small portion of the material was collected and tested for BRAF, RAS, RET/PTC, and PAX8/PPARgamma mutations. The mutational status was correlated with cytology and either surgical pathology diagnosis or follow-up (mean, 34 months).

RESULTS

A sufficient amount of nucleic acids were isolated in 98% of samples. Thirty-two mutations were found, including 18 BRAF, eight RAS, five RET/PTC, and one PAX8/PPARgamma. The presence of any mutation was a strong indicator of cancer because 31 (97%) of mutation-positive nodules had a malignant diagnosis after surgery. A combination of cytology and molecular testing showed significant improvement in the diagnostic accuracy and allowed better prediction of malignancy in the nodules with indeterminate cytology.

CONCLUSIONS

These results indicate that molecular testing of thyroid nodules for a panel of mutations can be effectively performed in a clinical setting. It enhances the accuracy of FNA cytology and is of particular value for thyroid nodules with indeterminate cytology.

Older age and larger tumor size predict malignancy in hürthle cell neoplasms of the thyroid

BACKGROUND

Hürthle cell neoplasms (HCNs) are rare tumors of the thyroid gland. The definitive treatment for Hürthle cell carcinoma (HCC) is total thyroidectomy, while thyroid lobectomy is adequate for Hürthle cell adenoma (HCA). However, differentiating HCC from HCA either before or during surgery is a challenge. The purpose of this study was to identify factors that predict malignancy in patients with HCN.

METHODS

Between May 1994 and January 2007, 1,199 patients underwent thyroid surgery at an academic medical center. Medical records of 55 consecutive patients who underwent thyroid resections for the preoperative diagnosis of HCN were reviewed.

RESULTS

Of the 55 patients with HCN, 46 (84%) had adenomas and 9 (16%) had carcinomas. Patients with HCC were significantly older than those with HCA (66 +/- 6 years versus 53 +/- 2 years, P = 0.01). Patients with carcinoma also had significantly larger thyroid nodules (4.5 +/- 0.7 cm versus 2.5 +/- 0.2 cm, P < 0.001). All HCNs less than 2 cm in diameter were benign. The malignancy rate increased with nodule size: 18% of nodules measuring 2-4 cm, and 44% of those larger than 4 cm were HCC. One patient with HCC had recurrence of the disease, but there were no disease-related deaths.

CONCLUSION

Advanced patient age and larger nodule size are two important factors that predict malignancy in patients with HCN. In patients with these and other known risk factors for HCC, total thyroidectomy should be considered.

The role of intraoperative frozen section if suspicious for papillary thyroid cancer

BACKGROUND

Optimal surgical intervention is straightforward when a fine-needle aspiration (FNA) is diagnostic for papillary thyroid cancer (PTC). However, if there are characteristics of an aspirate suspicious for PTC but not meeting criteria for diagnosis of PTC, the management is less clear.

METHODS

Of the 1,051 patients who underwent thyroid surgery at the University of Wisconsin between May 24, 1994, and October 21, 2004, 102 had preoperative FNA cytology that was diagnostic or suspicious for PTC. Within the subgroups of diagnostic for PTC and suspicious for PTC, we evaluated the accuracy of FNA, the utility of frozen section (FS), and the predictive value of demographic and pathologic variables.

RESULTS

When diagnostic for PTC, FNA was 97% accurate and FS did not alter management. However, if an FNA was interpreted as suspicious for PTC, there was a 57% (17/30) likelihood of PTC on permanent histology. In this subgroup, FS led to the optimal operative procedure in 96% (25/26) of cases. With the exception of size greater than 4 cm, demographic and pathologic variables did not predict malignancy or increase the likelihood of an FNA being diagnostic for PTC.

CONCLUSION

Intraoperative FS is a useful diagnostic tool when an FNA is suspicious for PTC.

Higher serum thyroid stimulating hormone level in thyroid nodule patients is associated with greater risks of differentiated thyroid cancer and advanced tumor stage

CONTEXT

TSH is a known thyroid growth factor, but the pathogenic role of TSH in thyroid oncogenesis is unclear.

OBJECTIVE

The aim was to examine the relationship between preoperative TSH and differentiated thyroid cancer (DTC).

DESIGN

The design was a retrospective cohort.

SETTING, PARTICIPANTS

Between May 1994 and January 2007, 1198 patients underwent thyroid surgery at a single hospital. Data from the 843 patients with preoperative serum TSH concentration were recorded.

MAIN OUTCOME MEASURES

Serum TSH concentration was measured with a sensitive assay. Diagnoses of DTC vs. benign thyroid disease were based on surgical pathology reports.

RESULTS

Twenty-nine percent of patients (241 of 843) had DTC on final pathology. On both univariate and multivariable analyses, risk of malignancy correlated with higher TSH level (P=0.007). The likelihood of malignancy was 16% (nine of 55) when TSH was less than 0.06 mIU/liter vs. 52% (15 of 29) when 5.00 mIU/liter or greater (P=0.001). When TSH was between 0.40 and 1.39 mIU/liter, the likelihood of malignancy was 25% (85 of 347) vs. 35% (109 of 308) when TSH was between 1.40 and 4.99 mIU/liter (P=0.002). The mean TSH was 4.9+/-1.5 mIU/liter in patients with stage III/IV disease vs. 2.1+/-0.2 mIU/liter in patients with stage I/II disease (P=0.002).

CONCLUSIONS

The likelihood of thyroid cancer increases with higher serum TSH concentration. Even within normal TSH ranges, a TSH level above the population mean is associated with significantly greater likelihood of thyroid cancer than a TSH below the mean. Shown for the first time, higher TSH level is associated with advanced stage DTC.

Follicular neoplasm of the thyroid--vanishing cytologic diagnosis?

The significance of making a diagnosis of follicular neoplasm on fine needle aspiration (FNA) biopsy remains a controversial issue, considering that the diagnosis of follicular carcinoma is based on histological criteria and the significantly decreasing incidence of follicular carcinoma in the general population. On FNA the main differential diagnoses of follicular neoplasm includes follicular variant of papillary carcinoma (FVPC), follicular adenoma, follicular carcinoma and benign solitary nodule occurring in a goiter. Several studies have looked at immunohistochemical and molecular markers to distinguish benign from malignant lesions but none of them have proved to be infallible. Although, FVPC is a distinct entity from the follicular neoplasm group, it is not always possible to separate it from the other follicular lesions because of overlapping cytologic features and often-sporadic presence of nuclear features, follicular variant of papillary carcinoma remains the main pitfall in a diagnosis of follicular neoplasm. Since a significant number of cases that are malignant on follow-up are usually FVPC, consequently, follicular neoplasm is an essential diagnostic consideration on FNA. In addition, follicular carcinoma, despite a decreasing incidence continues to be a real entity. Therefore, it is essential that follicular neoplasm continue to be part of our diagnostic repertoire.

Operative strategy for follicular thyroid cancer in risk groups stratified by pTNM staging

This study determined cancer survival rates and follow-up status at different pTNM stages to stratify risk groups in follicular thyroid carcinoma. Two hundred and fourteen follicular thyroid cancer patients (167 females, 47 males) who underwent surgery and followed-up treatment at a single medical center were enrolled in this retrospective study. Tumors were staged by UICC-TNM criteria (6th edition). Low risk for follicular thyroid cancer was defined as pT1N0M0. (Moderate-risk group) was defined as all other patients in pTNM stage I, and high risk as patients in stages II-IV. After mean follow-up of 9.6+/-0.3 years, 1.6% (2/120), 21.9% (7/32), 5.6% (1/18) and 52.3% (23/44) of patients in pTNM stages I-IV, respectively, died of thyroid cancer. Of 214 follicular thyroid cancer patients, 35 (16.4%), 85 (39.7%) and 94 (43.9%) were defined as low-, moderate- and high-risk groups at the time of surgery. None of the low-risk patients died, and all achieved disease-free status. In the moderate- and high-risk groups, 2.4% (2/85) and 27.7% (26/94) died of thyroid cancer. The moderate- and high-risk groups underwent near-total thyroidectomy and (131)I therapies, and 15 of 107 (14.9%) died of thyroid cancer while 18 (16.8%) had persistent disease at the end of the study period. Multiple regression analysis demonstrated that tumor size, radioactive iodide therapy and post-operative thyroglobulin level significantly differ between the mortality and survival groups. In conclusion, the low-risk follicular thyroid cancer group as defined by pTNM staging had excellent prognosis. Total thyroidectomy and post-operative radioactive iodide therapy are mandatory in moderate- and high-risk groups. Over one-fourth of the follicular thyroid cancer patients in the high-risk group died of thyroid cancer despite aggressive treatment.

The ongoing debate in thyroid surgery: should frozen section analysis be omitted?

Controversies concerning the role of frozen section (FS) have been a matter of debate. The aim of this study was to identify the role of FS analysis in intraoperative decision making and analyze the effect of the cost in detecting thyroid malignancies in Turkey. Out of 214 consecutive patients who had been operated on for thyroid cancer between January 1996 and August 2004, 178 patients were evaluated retrospectively. All 178 patients were subjected to FS. Intraoperative FS correctly identified the pathology as malignant in 58.4% of patients. A true-positive FS result changed the surgical strategy in 30 (27.6%) cases False negative FS lesions were defined histologically as papillary microcarcinoma in 54%, follicular variant of papillary cancer in 18% and follicular cancer in 8% of cases. The sensitivities of FNAB and intraoperative FS in thyroid cancer patients were 22.5% and 58.4%, respectively. False negative FS results increased the cost for each informative FS from euro25 to euro42.7. Despite limitations, results of this study reject the idea that the role of FS is becoming limited. We recommend routine frozen section in the operative assessment of thyroid nodules. Omitting FS may be suggested only in cases with a FNAB revealing malignancy.

Role of frozen section associated with intraoperative cytology in comparison to FNA and FS alone in the management of thyroid nodules

AIMS

The utilization of fine needle aspiration (FNA) biopsy is an accurate and cost-effective method in the diagnosis of thyroid diseases. However, the non-diagnostic cases and cases of suspicious carcinoma remain a dilemma, and in these cases thyroidectomy is usually recommended, even if only 15-20% of these patients really need a thyroidectomy. To avoid unnecessary surgical treatment, frozen section (FS) is usually performed. This method is well recognized, but is not useful for the diagnosis of follicular lesions. Therefore, many authors have tried to increase the specificity and sensibility of intraoperative examination, supporting it with an intraoperative cytological technique (IC). To clarify the role of intraoperative exam (FS and IC), also comparing to FNA, we have reviewed our own experiences.

METHODS

In a period covering 6 years (2000-2005), FS was performed in 1,472 cases out of 11,420 total thyroidectomy operations. FS diagnosis and definitive diagnosis, were reviewed and confirmed, moreover, FNA diagnosis and definitive diagnosis were also considered and all intraoperatory cytological slides were reviewed. Diagnostic accuracy was assessed for FNA and FS with or without intraoperative cytology. We compared 1,472 FS diagnoses with their definitive histological diagnosis; 728 FNA out of 1,472 patients with definitive histological diagnosis, and 564 FS associated with IC out of 1,472 patients with definitive diagnosis.

RESULTS

The diagnostic accuracy of these three methods were, respectively, 88.8%, 88.8% and 95.7%.

CONCLUSION

We can assert that FS associated with IC remains the most accurate technique in the surgical management of thyroid nodules.

Surgical Treatment of Solitary Thyroid Nodules Via Fine-Needle Aspiration Biopsy and Frozen-Section Analysis

BACKGROUND

Fine-needle aspiration biopsy (FNAB) and frozen-section analysis of managing solitary thyroid nodules continue to generate considerable controversy.

METHODS

This study was a retrospective review of 619 patients with solitary thyroid nodules who underwent thyroidectomy.

RESULTS

Of 540 FNABs, 35 (6.5%) were positive for malignancy, 276 (51.1%) were benign, and 229 (42.4%) were suspicious. Only 5.1% were false negative, and 11.4% were false positive. Diagnostic FNAB sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy for malignancy were 86.1%, 59.7%, 33.0%, 94.9%, and 64.6%, respectively. Of 569 patients analyzed by frozen section, diagnosis was deferred in 86 (15.1%) patients, and results were positive for malignancy in 92 (16.2%) and benign in 391 (68.7%). No false-positive results were noted, but 2.3% (391) were false negative. Of 86 deferred frozen sections, 11 (12.8%) patients had malignant tumors confirmed by permanent section. Diagnostic frozen-section sensitivity, specificity, PPV, NPV, and accuracy for carcinoma were 82.1%, 100%, 100%, 95.8%, and 96.5%, respectively. Sensitivity, specificity, PPV, NPV, and accuracy for frozen-section analysis for diagnosis of carcinoma in patients with suspicious FNAB were 83.9%, 100%, 100%, 94.9%, and 96.0%, respectively.

CONCLUSIONS

FNAB is a sensitive diagnostic modality in selecting patients who require surgery. Routine use of frozen-section analysis is unwarranted for benign FNAB results. Frozen section is specific and cost-effective in determining the extent of surgery in patients with suspicious or malignant FNABs.

The surgical management of Graves' disease

BACKGROUND

The historical aspects of the pathophysiology and treatment of Graves' disease are briefly discussed in this paper.

MATERIALS AND METHODS

The three treatment modalities of Graves' disease are anti-thyroid drug therapy, radioactive iodine therapy, and surgery. Although the majority of patients with Graves' disease in the U.S. are treated with radioactive iodine, surgery still plays an important role when patients cannot tolerate anti-thyroid drug therapy, when medical treatment is rejected by patients, or when surgery is deemed the fastest and safest route in managing the patient.

CONCLUSIONS

The indications for surgical management of Graves' disease are discussed with emphasis on available data supporting the extent of thyroid resection based on the incidences of hypothyroidism, recurrence of hyperthyroidism, recurrent laryngeal nerve injury and hypoparathyroidism.

Contemporary management of differentiated thyroid carcinoma

This article reviews the recent changes affecting the care of patients with well-differentiated thyroid carcinoma. The impacts of positron emission tomographic imaging, recombinant human thyroid stimulating hormone,and current surgical management standards are discussed.