Can Ethanol Ablation Achieve Durable Control of Neck Nodal Recurrences in Adults With Stage I Papillary Thyroid Cancer?

Objective

Results of ethanol ablation (EA) for controlling neck nodal metastases (NNM) in adult patients with papillary thyroid carcinoma (APTC) beyond 6 months have rarely been reported. We now describe outcome results in controlling 71 NNM in 40 node-positive stage I APTC patients followed for 66 to 269 months.

Methods

All 40 patients were managed with bilateral thyroidectomy and radioiodine therapy and followed with neck ultrasound (US) for >48 months after EA. Cumulative radioiodine doses ranged from 30 to 550 mCi; pre-EA 27 patients (67%) had 36 additional neck surgeries. Cytologic diagnosis of PTC in 71 NNM selected for EA was confirmed by US-guided biopsy. EA technique and follow-up protocol were as previously described.

Results

The 40 patients had 1 to 4 NNM; 67/71 NNM (94%) received 2 to 4 ethanol injections (total median volume 0.8 cc). All ablated 71 NNM shrank (mean volume reduction of 93%); nodal hypervascularity was eliminated. Thirty-eight NNM (54%) with initial volumes of 12-1404 mm3 (median 164) disappeared on neck sonography. Thirty-three hypovascular foci from ablated NNM (pre-EA volume range 31-636 mm3; median 147) were still identifiable with volume reductions of 45% to 97% observed (median 81%). There were no complications and no postprocedure hoarseness. Final results were considered to be ideal or near ideal in 55% and satisfactory in 45%. There was no evidence of tumor regrowth after EA.

Conclusion

Our results demonstrate that for patients with American Joint Committee on Cancer stage I APTC, who do not wish further surgery or radioiodine, and are uncomfortable with active surveillance, EA can achieve durable control of recurrent NNM.

Long-term Effectiveness of Ethanol Ablation in Controlling Neck Nodal Metastases in Childhood Papillary Thyroid Cancer

Context

Childhood papillary thyroid carcinoma (CPTC), despite bilateral thyroidectomy, nodal dissection and radioiodine remnant ablation (RRA), recurs within neck nodal metastases (NNM) in 33% within 20 postoperative years. These NNM are usually treated with reoperation or further radioiodine. Ethanol ablation (EA) may be considered when numbers of NNM are limited.

Objective

We studied the long-term results of EA in 14 patients presenting with CPTC during 1978 to 2013 and having EA for NNM during 2000 to 2018.

Methods

Cytologic diagnoses of 20 NNM (median diameter 9 mm; median volume 203 mm³) were biopsy proven. EA was performed during 2 outpatient sessions under local anesthesia; total volume injected ranged from 0.1 to 2.8 cc (median 0.7). All were followed regularly by sonography and underwent volume recalculation and intranodal Doppler flow measurements. Successful ablation required reduction both in NNM volume and vascularity.

Results

Post EA, patients were followed for 5 to 20 years (median 16). There were no complications, including postprocedure hoarseness. All 20 NNM shrank (mean by 87%) and Doppler flow eliminated in 19 of 20. After EA, 11 NNM (55%) disappeared on sonography; 8 of 11 before 20 months. Nine ablated foci were still identifiable after a median of 147 months; only one identifiable 5-mm NNM retained flow. Median serum Tg post EA was 0.6 ng/mL. Only one patient had an increase in Tg attributed to lung metastases.

Conclusion

EA of NNM in CPTC is effective and safe. Our results suggest that for CPTC patients who do not wish further surgery and are uncomfortable with active surveillance of NNM, EA represents a minimally invasive outpatient management option.

Radioiodine remnant ablation in stage I adult papillary thyroid carcinoma: does it improve postoperative outcome?

Objective

To determine whether radioiodine remnant ablation (RRA) reduces cause-specific mortality (CSM) or tumor recurrence rates (TRR) after potentially curative bilateral thyroidectomy (BT) in low-risk adult papillary thyroid carcinoma (APTC) patients, we compared postoperative outcomes in 1836 pTNM stage I APTC patients having BT alone with 832 having BT+RRA during two consecutive 25-year periods.

Methods

The THEN cohort (consecutively managed during 1966-1990) comprised 809 patients (36% having BT+RRA) and the NOW cohort (1991-2015) comprised 1859 patients (29% BT+RRA). Analyses of differences in occurrence rates between BT alone and BT+RRA patients were performed with SAS software.

Results

During 1966-1990, when RRA rates rose ten-fold, 20-year CSM after BT alone was 0.6% and after BT+RRA was 1.2% (P = 0.66); during 1991-2015, when RRA rates progressively fell, no PTC deaths occurred in 1859 patients. In the THEN cohort, RRA did not significantly improve TRR at local, regional, or distant sites (P > 0.1), when compared to BT alone. RRA in NOW cohort was administered to 49% of node-positive (pN1) patients and 17% of node-negative (pN0/NX) patients (P < 0.0001); TRR therefore, were examined separately for pN0/NX and pN1 patients. In 1157 pN0/NX cases, 20-year locoregional TRR were 3.1% after BT and were higher (P = 0.049) at 8.6% after BT+RRA. In four pN1 groups, stratified by metastatic nodal burden, RRA did not significantly reduce the locoregional TRR observed after BT with curative intent (P > 0.5).

Conclusions

In a 5-decade experience, RRA administered postoperatively to stage I APTC patients did not reduce either CSM or TRR and should probably not be indicated when such patients undergo potentially curative BT.

Incidence of Clinically Relevant Thyroid Cancers Remains Stable for Almost a Century: A Population-Based Study

OBJECTIVE

To examine the trends in incidence of clinically relevant thyroid cancers within the overall rising incidence of thyroid cancers.

PATIENTS AND METHODS

This is a population-based cohort study conducted using the Rochester Epidemiology Project database to identify all new cases of thyroid cancer in Olmsted County, Minnesota, between January 1, 1935, and December 31, 2018. We extracted information about demographics and tumor pathologic type, size, and invasiveness. Clinically relevant cancers included aggressive histology or presence of metastatic disease, size larger than 4 cm, and gross extrathyroidal tumor invasion.

RESULTS

Between 1935 and 2018, 596 thyroid cancer cases were diagnosed (mean age, 46.4 years; 72% female; 87% papillary cancers; and median tumor size, 1.5 cm). The sex- and age-adjusted incidence of thyroid cancer increased from 1.3 per 100,000 person-years (p-y) from 1935-1949 to 12.0 per 100,000 p-y in 2010-2018, corresponding to an absolute change per decade of 1.4 (95% CI, 0.7 to 2.2). There was a nonsignificant period absolute change for patients with tumor greater than 4 cm (0.03; 95% CI, -0.2 to 0.3), with evidence of tumor invasion (0.1; 95% CI, -0.1 to 0.4), and with aggressive histology or presence of metastatic disease (0.2; 95% CI, -0.1 to 0.6). Thyroid cancer mortality was unchanged over the observation period.

CONCLUSION

Incidence rates of clinically relevant thyroid cancers, as defined by histology, size, and invasiveness, have not changed significantly in 80 years. The rising thyroid cancer incidence is driven by indolent thyroid cancers.

Inability of Radioiodine Remnant Ablation to Improve Postoperative Outcome in Adult Patients with Low-Risk Papillary Thyroid Carcinoma

OBJECTIVE

To determine whether radioiodine remnant ablation (RRA) reduces cause-specific mortality (CSM) or tumor recurrence (TR) rate after bilateral lobar resection (BLR).

PATIENTS AND METHODS

There were 2952 low-risk adult papillary thyroid cancer (LRAPTC) patients (with MACIS scores <6) who underwent potentially curative BLR during 1955-2014. During 1955-1974, 1975-1994, and 1995-2014, RRA was administered in 3%, 49%, and 28%. Statistical analyses were performed using SAS software.

RESULTS

During 1955-1974, the 20-year CSM and TR rates after BLR alone were 1.0% and 6.8%; rates after BLR+RRA were 0% (P=.63) and 5.9% (P=.82). During 1975-1994, post-BLR 20-year rates for CSM and TR were 0.3% and 7.5%; after BLR+RRA, rates were higher at 0.9% (P=.31) and 12.8% (P=.01). When TR rates were examined separately for 448 node-negative and 317 node-positive patients, differences were nonsignificant. In 1995-2014, post-BLR 20-year CSM and TR rates were 0% and 9.2%; rates after BLR+RRA were higher at 1.4% (P=.19) and 21.0% (P<.001). In 890 pN0 cases, 15-year locoregional recurrence rates were 3.4% after BLR and 3.7% after BLR+RRA (P=.99). In 740 pN1 patients, 15-year locoregional recurrence rates were 10% higher after BLR+RRA compared with BLR alone (P=.01). However, this difference became nonsignificant when stratified by numbers of metastatic nodes.

CONCLUSION

RRA administered to LRAPTC patients during 1955-2014 did not reduce either the CSM or TR rate. We would therefore not recommend RRA in LRAPTC patients undergoing BLR with curative intent.

Predicting Outcomes in Sporadic and Hereditary Medullary Thyroid Carcinoma over Two Decades

Background: Medullary thyroid cancer (MTC) can be associated with significant morbidity and mortality in advanced cases. Hence, we aimed to identify factors at the time of MTC surgery that predict overall survival (OS), disease-specific survival (DSS), locoregional recurrence/persistence (LR), and distant metastases (DM). Methods: We performed a retrospective study of clinicopathologic, radiological, and laboratory data in MTC patients who underwent thyroidectomy at Mayo Clinic from January 1995 to December 2015. Results: We identified 163 patients (mean age 48.4 years, 48% males), 102 with sporadic MTC and 61 with hereditary disease (n = 46 multiple endocrine neoplasia [MEN] 2A, n = 3 MEN 2B, n = 12 familial MTC) with a median follow-up time of 5.5 years. On univariate analysis, age >55 years, male sex, DM at the time of surgery (M1), lateral neck lymph node (LN) involvement (N1b), gross extrathyroidal extension (ETE), American Joint Committee on Cancer (AJCC) stage 3/4, tumor size (T) 3/4, tumor size, and postoperative calcitonin (Ctn) and carcinoembryonic antigen (CEA) were significant predictors of worse OS and DSS. On multivariable analysis, both gross ETE (hazard ratio [HR] 4.62, 6.58) and M1 (HR 5.11, 10.45) remained significant predictors of worse OS as well as DSS, while age >55 years (HR 3.21), male sex (HR 2.42), and postoperative Ctn (HR 1.002 for every 100 pg/mL increase) were significant only for worse OS. On univariate analysis, male sex, M1, N1b, gross ETE, stage 3/4, T 3/4, tumor size, number of LNs involved, and postoperative Ctn were significant predictors of LR and DM; age >55 years was additionally significant for DM. On multivariable analysis, gross ETE (HR 3.16, 5.93) and N1b (HR 4.31, 4.64) remained significant predictors of LR and DM; ratio of resected/involved LN (HR 10.91) was additionally predictive for LR and postoperative Ctn (HR 1.003 for every 100 pg/mL increase) for DM. Conclusions: Disease burden at initial surgery, especially gross ETE, lateral neck LN involvement, and DM, as well as the biochemical response to surgery appear to be more important than demographic factors in terms of MTC prognosis. These findings highlight the importance of rigorous perioperative assessment to better predict MTC outcomes.

Long-Term Results of Treating With Ethanol Ablation 15 Adult Patients With cT1aN0 Papillary Thyroid Microcarcinoma

Background

Currently acceptable management options for patients with adult papillary thyroid microcarcinoma (APTM) range from immediate surgery, either unilateral lobectomy or bilateral lobar resection, to active surveillance (AS). An alternative minimally invasive approach, originally employed for eliminating neck nodal metastases, may be ultrasound-guided percutaneous ethanol ablation (EA). Here we present our experience of definitively treating with EA 15 patients with APTM.

Patients and Methods

During 2010 through 2017, the 15 cT1aN0M0 patients selected for EA were aged 36 to 86 years (median, 45 years). Tumor volumes (n = 17), assessed by sonography, ranged from 25 to 375 mm³ (median, 109 mm³). Fourteen of 15 patients had 2 ethanol injections on successive days; total volume injected ranged from 0.45 to 1.80 cc (median, 1.1 cc). All ablated patients were followed with sonography and underwent recalculation of tumor volume and reassessment of tumor perfusion at each follow-up visit.

Results

The ablated patients have now been followed for 10 to 100 months (median, 64 months). There were no complications and no ablated patient developed postprocedure recurrent laryngeal nerve dysfunction. All 17 ablated tumors shrank (median 93%) and Doppler flow eliminated. Median tumor volume reduction in 9 identifiable avascular foci was 82% (range, 26%-93%). After EA, 8 tumors (47%) disappeared on sonography after a median of 10 months. During follow-up no new PTM foci and no nodal metastases have been identified.

Conclusions

Definitive treatment of APTM by EA is effective, safe, and inexpensive. Our results suggest that, for APTM patients who do not wish neck surgery and are uncomfortable with AS, EA represents a well-tolerated and minimally invasive outpatient management option.

Elimination of Locoregional Recurrences and Skin Metastases in Papillary Thyroid Cancer by Ethanol Ablation and Mohs Surgery

Ultrasound-guided percutaneous ethanol ablation procedures for locoregional recurrences in papillary thyroid carcinoma (PTC) can be repeatedly performed over years. Skin metastases (SM) from PTC generally portend a lethal prognosis. Our patient case report demonstrates the innovative use in low-risk PTC (LRPTC) of treatment modalities designed to prevent neck re-explorations and capable of eliminating both locoregional recurrences and SM. In 2004, a 48-year-old man presented with neck nodal metastases due to PTC. He underwent a near-total thyroidectomy and nodal dissection, confirming an 8-mm PTC involving 2 ipsilateral node metastases. Postoperatively, he received 2 doses of radioactive iodine (RAI) for remnant uptake (cumulative dose 338 mCi); posttherapy scanning was unrevealing. In 2007, he underwent right neck dissection for further node metastases. In 2008, a guided biopsy confirmed a level IV node metastasis. He was referred to our institution for ethanol ablation. Two node metastases were ablated and subsequently disappeared. During 2010-2016, he developed an additional 6 node metastases, which were treated with ethanol ablation; all disappeared on high-resolution sonography. FDG-PET-CT scans in 2009 and 2016 were negative for distant spread. In 2016, a SM in his right neck was removed by dermatologic surgery. In 2017-2018, 2 further SM were excised with negative margins, one after Mohs surgery. He has now been disease-free for 20 months. In conclusion, despite 3 neck surgeries and 2 RAI therapies, our patient repeatedly developed both locoregional recurrences and SM. All 11 disease foci were eliminated with minimally invasive procedures which should more often be considered as effective treatment options in LRPTC.

The role of radioactive iodine in the management of patients with differentiated thyroid cancer - An oncologic surgical perspective

With improved understanding of the biology of differentiated thyroid carcinoma its management is evolving. The approach to surgery for the primary tumour and elective nodal surgery is moving from a "one-size-fits-all" recommendation to a more personalised approach based on risk group stratification. With this selective approach to initial surgery, the indications for adjuvant radioactive iodine (RAI) therapy are also changing. This selective approach to adjuvant therapy requires understanding by the entire treatment team of the rationale for RAI, the potential for benefit, the limitations of the evidence, and the potential for side-effects. This review considers the evidence base for the benefits of using RAI in the primary and recurrent setting as well as the side-effects and risks from RAI treatment. By considering the pros and cons of adjuvant therapy we present an oncologic surgical perspective on selection of treatment for patients, both following pre-operative diagnostic biopsy and in the setting of a post-operative diagnosis of malignancy.

Management of Papillary Thyroid Microcarcinoma

The worldwide incidence of thyroid cancer is increasing. A third of new thyroid cancer cases are papillary thyroid microcarcinoma (PTM), which are 1 cm or less. These tumors are mostly indolent with excellent prognosis. Although thyroid surgery is the most common management option for patients with PTM, new management options demand that treatment decisions must be individualized and based on patient's preference, context, and biology. This article describes management options for PTM patients and shared decision-making as a novel method for individualizing care.

Papillary Thyroid Carcinoma (PTC) in Children and Adults: Comparison of Initial Presentation and Long-Term Postoperative Outcome in 4432 Patients Consecutively Treated at the Mayo Clinic During Eight Decades (1936-2015)

BACKGROUND

Contemporary guidelines for managing PTC advise an approach wherein primary tumor and regional metastases (RM) are completely resected at first surgery and radioiodine remnant ablation (RRA) is restricted to high-risk patients, policies our group has long endorsed. To assess our therapeutic efficacy, we studied 190 children and 4242 adults consecutively treated during 1936-2015.

SUBJECTS AND METHODS

Mean follow-up durations for children and adults were 26.9 and 15.2 years, respectively. Bilateral lobar resection was performed in 86% of children and 88% of adults, followed by RRA in 30% of children and 29% of adults; neck nodes were excised in 86% of children and 66% of adults. Tumor recurrence (TR) and cause-specific mortality (CSM) details were taken from a computerized database.

RESULTS

Children, when compared to adults, had larger primary tumors which more often were grossly invasive and incompletely resected. At presentation, children, as compared to adults, had more RM and distant metastases (DM). Thirty-year TR rates were no different in children than adults at any site. Thirty-year CSM rates were lower in children than adults (1.1 vs. 4.9%; p = 0.01). Comparing 1936-1975 (THEN) with 1976-2015 (NOW), 30-year CSM rates were similar in MACIS <6 children (p = 0.67) and adults (p = 0.08). However, MACIS <6 children and adults in 1976-2015 had significantly higher recurrence at local and regional, but not at distant, sites. MACIS 6+ adults, NOW, compared to THEN, had lower 30-year CSM rates (30 vs. 47%; p < 0.001), unassociated with decreased TR at any site.

CONCLUSIONS

Children, despite presenting with more extensive PTC when compared to adults, have postoperative recurrences at similar frequency, typically coexist with DM and die of PTC less often. Since 1976, both children and adults with MACIS <6 PTC have a <1% chance at 30 years of CSM; adults with higher MACIS scores (6 or more) have a 30-year CSM rate of 30%.

Follicular cell-derived thyroid cancer

Follicular cell-derived thyroid cancers are derived from the follicular cells in the thyroid gland, which secrete the iodine-containing thyroid hormones. Follicular cell-derived thyroid cancers can be classified into papillary thyroid cancer (80-85%), follicular thyroid cancer (10-15%), poorly differentiated thyroid cancer (<2%) and undifferentiated (anaplastic) thyroid cancer (<2%), and these have an excellent prognosis with the exception of undifferentiated thyroid cancer. The advent and expansion of advanced diagnostic techniques has driven and continues to drive the epidemic of occult papillary thyroid cancer, owing to overdiagnosis of clinically irrelevant nodules. This transformation of the thyroid cancer landscape at molecular and clinical levels calls for the modification of management strategies towards personalized medicine based on individual risk assessment to deliver the most effective but least aggressive treatment. In thyroid cancer surgery, for instance, injuries to structures outside the thyroid gland, such as the recurrent laryngeal nerve in 2-5% of surgeries or the parathyroid glands in 5-10% of surgeries, negatively affect quality of life more than loss of the expendable thyroid gland. Furthermore, the risks associated with radioiodine ablation may outweigh the risks of persistent or recurrent disease and disease-specific mortality. Improvement in the health-related quality of life of survivors of follicular cell-derived thyroid cancer, which is decreased despite the generally favourable outcome, hinges on early tumour detection and minimization of treatment-related sequelae. Future opportunities include more widespread adoption of molecular and clinical risk stratification and identification of actionable targets for individualized therapies.

The Impact of Subclinical Disease and Mechanism of Detection on the Rise in Thyroid Cancer Incidence: A Population-Based Study in Olmsted County, Minnesota During 1935 Through 2012

BACKGROUND

An ongoing epidemic of thyroid carcinoma (TC) has affected Americans since 1975. Understanding the contribution of subclinical disease and the mechanism of such disease detection may help to alter the course of this epidemic.

METHODS

We used Rochester Epidemiology Project resources to examine the incidence of TC cases, disease specific mortality, and method of diagnosis during 1935 through 2012. During 2000-2012, we also extracted the mechanism of detection of clinically occult tumors.

RESULTS

The age-adjusted incidence (AAI) for TC increased from 7.1 [95% confidence interval (CI) 5.5-8.8] per 100,000 person-years (p-y) during 1990-1999 to 13.7 [CI 11.8-15.6] per 100,000 p-y during 2000-2012, with no change in disease-specific mortality since 1935. The incidence trend analysis stratified by the mechanism of detection revealed the AAI of clinically recognized TC was 5.5 per 100,000 p-y [CI 3.4-7.5] in 1960-1969, a rate similar to the incidence seen during 2000-2012. However, AAI of clinically occult TC increased from 0.2 per 100,000 p-y [CI 0.0-0.6] in 1935-1949 to 1.9 per 100,000 p-y [CI 1.2-2.9] in 1990-1999 and to 7.4 per 100,000 p-y [CI 6.0-8.8] in 2000-2012. During 2000-2012, the most frequent reasons for recognition of "occult" tumors were (1) incidental discovery during diagnostic neck imaging in 40 (19%), (2) pathology review of specimens from thyroid surgery for benign conditions in 29 (14%), and (3) investigations of patients with symptoms or palpable nodules that were clearly not associated with coexistent but occult TC but triggered the use of diagnostic neck imaging in 37 (27%).

CONCLUSIONS

In this population-based study conducted in Olmsted County, Minnesota, the rapid increased incidence of TC during 2000-2012 can be completely attributed to the increased diagnosis of occult TCs, which are mainly found through the use of diagnostic neck imaging. The incidence of clinical TC and disease-specific TC mortality remains stable since 1970, implying that the observed increased incidence is due to the increased detection of subclinical lesions.

Management Guidelines for Children with Thyroid Nodules and Differentiated Thyroid Cancer

BACKGROUND

Previous guidelines for the management of thyroid nodules and cancers were geared toward adults. Compared with thyroid neoplasms in adults, however, those in the pediatric population exhibit differences in pathophysiology, clinical presentation, and long-term outcomes. Furthermore, therapy that may be recommended for an adult may not be appropriate for a child who is at low risk for death but at higher risk for long-term harm from overly aggressive treatment. For these reasons, unique guidelines for children and adolescents with thyroid tumors are needed.

METHODS

A task force commissioned by the American Thyroid Association (ATA) developed a series of clinically relevant questions pertaining to the management of children with thyroid nodules and differentiated thyroid cancer (DTC). Using an extensive literature search, primarily focused on studies that included subjects ≤18 years of age, the task force identified and reviewed relevant articles through April 2014. Recommendations were made based upon scientific evidence and expert opinion and were graded using a modified schema from the United States Preventive Services Task Force.

RESULTS

These inaugural guidelines provide recommendations for the evaluation and management of thyroid nodules in children and adolescents, including the role and interpretation of ultrasound, fine-needle aspiration cytology, and the management of benign nodules. Recommendations for the evaluation, treatment, and follow-up of children and adolescents with DTC are outlined and include preoperative staging, surgical management, postoperative staging, the role of radioactive iodine therapy, and goals for thyrotropin suppression. Management algorithms are proposed and separate recommendations for papillary and follicular thyroid cancers are provided.

CONCLUSIONS

In response to our charge as an independent task force appointed by the ATA, we developed recommendations based on scientific evidence and expert opinion for the management of thyroid nodules and DTC in children and adolescents. In our opinion, these represent the current optimal care for children and adolescents with these conditions.

Clinical and molecular features of Hürthle cell carcinoma of the thyroid

CONTEXT

Hürthle cell cancer (HCC) of the thyroid remains the subject of controversy with respect to natural course, treatment, and follow-up.

OBJECTIVE

The objective of the study was to evaluate the clinical and molecular features associated with outcome in HCC.

DESIGN

The study was a review of 173 HCC cases treated at Mayo Clinic over 11 years with a median 5.8-year follow-up.

RESULTS

None of the patients with minimally invasive histology had persistent disease, clinical recurrence, or disease-related death. Male gender and TNM stage were independently associated with increased risk of clinical recurrence or death in widely invasive patients. The 5-year cumulative probability of clinical recurrence or death was higher in patients with TNM stage III-IV (females, 74%; males, 91%) compared with patients with TNM stage I-II (females, 0%; males, 17%). Pulmonary metastases were best identified by computed tomography, whereas radioactive iodine scans were positive in only two of 27 cases. Thyroglobulin was detectable in patients with clinical disease, with the notable exception of five patients with distant metastases. The common TERT C228T promoter mutation was detected in both widely invasive and minimally invasive tumors. TERT mRNA was below the limit of detection in all samples.

CONCLUSION

Widely invasive HCC with TNM stage III-IV is aggressive, with low probability of recurrence-free survival. Males have worse outcomes than females. Minimally invasive HCC appears to be considerably less aggressive. Radioactive iodine scan performs poorly in detecting distant disease. Although the TERT gene is mutated in HCC, the role of this mutation remains to be demonstrated.

Low risk papillary thyroid cancer

Thyroid cancer is one of the fastest growing diagnoses; more cases of thyroid cancer are found every year than all leukemias and cancers of the liver, pancreas, and stomach. Most of these incident cases are papillary in origin and are both small and localized. Patients with these small localized papillary thyroid cancers have a 99% survival rate at 20 years. In view of the excellent prognosis of these tumors, they have been denoted as low risk. The incidence of these low risk thyroid cancers is growing, probably because of the use of imaging technologies capable of exposing a large reservoir of subclinical disease. Despite their excellent prognosis, these subclinical low risk cancers are often treated aggressively. Although surgery is traditionally viewed as the cornerstone treatment for these tumors, there is less agreement about the extent of surgery (lobectomy v near total thyroidectomy) and whether prophylactic central neck dissection for removal of lymph nodes is needed. Many of these tumors are treated with radioactive iodine ablation and thyrotropin suppressive therapy, which-although effective for more aggressive forms of thyroid cancer-have not been shown to be of benefit in the management of these lesions. This review offers an evidence based approach to managing low risk papillary thyroid cancer. It also looks at the future of promising alternative surgical techniques, non-surgical minimally localized invasive therapies (ethanol ablation and laser ablation), and active surveillance, all of which form part of a more individualized treatment approach for low risk papillary thyroid tumors.

Pediatric endocrine surgery: a 20-year experience at the Mayo Clinic

CONTEXT

Surgically managed endocrinopathies are rare in children. Most surgeons have limited experience in this field. Herein we report our operative experience with pediatric patients, performed over two decades by high-volume endocrine surgeons.

SETTING

The study was conducted at the Mayo Clinic (a tertiary referral center).

PATIENTS

Patients were <19 years old and underwent an endocrine operation (1993-2012).

MAIN OUTCOME MEASURES

Demographics, surgical procedure, diagnoses, morbidity, and mortality were retrospectively reviewed.

RESULTS

A total of 241 primary cases included 177 thyroid procedures, 13 neck dissections, 24 parathyroidectomies, 14 adrenalectomies, 7 paragangliomas, and 6 pancreatic procedures. Average age of patients was 14.2 years. There were 133 total thyroidectomies and 40 hemithyroidectomies. Fifty-three cases underwent a central or lateral neck dissection. Six-month follow-up was available for 98 total thyroidectomy patients. There were four cases of permanent hypoparathyroidism (4%) and no permanent recurrent laryngeal nerve (RLN) paralyses. Sequelae of neck dissections included temporary RLN neurapraxia and Horner's syndrome. Parathyroidectomy was performed on 24 patients: 20 with primary hyperparathyroidism (HPT), three with tertiary HPT, and one with familial hypocalciuric hypocalcemia. Three patients (16%) had recurrent HPT, all with multiglandular disease. One patient had temporary RLN neurapraxia. We performed seven bilateral and seven unilateral adrenalectomies; eight were laparoscopic. Indications included pheochromocytoma, Cushing's syndrome, adrenocortical carcinoma, congenital adrenal hyperplasia, and ganglioneuroma. One death was due to adrenocortical carcinoma. Five paraganglioma patients had succinate dehydrogenase subunit B mutations, and one recurred. Six patients with insulinoma underwent enucleation (n = 5) or distal pancreatectomy (n = 1). A single postoperative abscess was managed nonoperatively.

CONCLUSION

Pediatric endocrine procedures are uncommon but can be safely performed with complication rates comparable to those of the adult population. It is imperative that these operations be performed by high-volume surgeons.

Invasive fibrous thyroiditis (Riedel thyroiditis): the Mayo Clinic experience, 1976-2008

BACKGROUND

Invasive fibrous thyroiditis (IFT) is the rarest form of thyroiditis, and reports are often limited to case reports and small case series. In this study, we aimed to summarize our institutional experience with IFT since 1976.

METHODS

We retrospectively reviewed the cases of all patients with IFT evaluated at Mayo Clinic, Rochester, Minnesota, from 1976 through 2008, with special emphasis on clinical presentation, associated risk factors, associated comorbid conditions, complications, and treatment.

RESULTS

Twenty-one patients met our inclusion criteria of (i) IFT confirmed by pathologic review at our institution and (ii) evidence of extension of fibrosis outside the thyroid capsule. Most patients (17, 81%) were women (mean age, 42 years). Presenting symptoms included pain (24%), dysphagia (33%), vocal cord paralysis (29%), and tracheal narrowing (48%). Three patients had associated hypoparathyroidism. Sixteen (76%) had a history of tobacco use, and 10 (48%) were current smokers. Fibrosing mediastinitis was present in four, orbital fibrosis in one, retroperitoneal fibrosis in three, and pancreatic fibrosis in one (38% had extracervical fibrotic processes). Eighteen patients had partial thyroidectomy, 7 (39%) of whom had surgical complications involving vocal cords and parathyroid. Two required tracheostomy. Thirteen had corticosteroid therapy; six received tamoxifen. There was no cause-specific mortality, and the fibrotic process stabilized or partially resolved in all patients.

CONCLUSIONS

IFT often is associated with a systemic extracervical fibrotic process and tobacco use. Attempted thyroid resection often results in postoperative complications. Long-term follow-up showed no deaths from IFT and showed stability of the thyroiditis.

Enhanced survival in locoregionally confined anaplastic thyroid carcinoma: a single-institution experience using aggressive multimodal therapy

BACKGROUND

Historical outcomes in anaplastic thyroid carcinoma (ATC) are poor, with a median survival of only 5 months and <20% of patients surviving 1 year from diagnosis. We hypothesized that survival in newly diagnosed patients with stages IVA and IVB locoregionally confined ATC might be improved by utilizing an aggressive therapeutic approach, prioritizing both the eradication of disease in the neck and preemptive treatment of occult metastatic disease.

METHODS

Between January 1, 2003, and December 31, 2007, 25 new ATC patients were evaluated at our institution. Of these 25 patients, 10 (40%) had metastatic disease at diagnosis and therefore underwent palliative treatment, whereas 5 (20%) had regionally confined disease and desired treatment at their local medical facilities. The remaining 10 consecutive patients (40%) had regionally confined ATC and elected aggressive therapy combining individualized surgery (where feasible), intensity-modulated radiation therapy (IMRT), and radiosensitizing + adjuvant chemotherapy intending four cycles of docetaxel + doxorubicin. Outcomes were assessed on an intention to treat basis.

RESULTS

There were no deaths from therapy, but hospitalization was required in two patients (20%) because of treatment-related adverse events. Five patients (50%) are alive and cancer-free, all having been followed >32 months (range: 32-89 months; median: 44 months) with a median overall Kaplan-Meier survival of 60 months. Overall survival at 1 and 2 years was 70% and 60%, respectively, compared to <20% historical survival at 1 year in analogous patients previously treated with surgery and conventional postoperative radiation at our and other institutions.

CONCLUSIONS

Although based upon a small series of consecutively treated patients, an aggressive approach combining IMRT and radiosensitizing plus adjuvant chemotherapy appears to improve outcomes, including survival in stages IVA and IVB regionally confined ATC, but remains of uncertain benefit in patients with stage IVC (metastatic) disease. Also uncertain is the optimal chemotherapy regimen to use in conjunction with IMRT. Further multicenter randomized trials are required to define optimal therapy in this rare but deadly cancer.

Cystic change in thyroid carcinoma: Prevalence and estimated volume in 360 carcinomas

PURPOSE

The aim of this study was to determine the prevalence and amount of cystic change in thyroid cancer. This study also examined associated sonographic characteristics of cystic malignant thyroid nodules to help recognize these clinically important nodules.

METHODS

This study was a retrospective review of 360 malignant thyroid nodules surgically removed at our institution between January 1, 2002 and December 31, 2004. All patients had signed research authorization. All patients had preoperative sonograms and surgical pathologic proof of their thyroid malignancy. The 360 malignant nodules were found in 307 patients. All scans were performed using 7- to 15-MHz transducers, and most studies included a digital video clip of the cancer. The preoperative ultrasound examinations were retrospectively reviewed by three radiologists and a sonographer. An estimate of cystic component percentage was derived by consensus. The presence of a mural nodule, thick irregular wall, microcalcifications, and prominent vascularity was also recorded.

RESULTS

Of the 360 carcinomas, 318 (88.3%) were solid to minimally (less than 5%) cystic, 33 (9.2%) were 6-50% cystic, 9 (2.5%) were 51-100% cystic. Of the nine (2.5%) malignancies that were greater than 50% cystic, all had other suspicious findings including mural nodules, microcalcifications, increased vascularity, and/or a thick irregular wall about the cystic portion.

CONCLUSION

The vast majority (88%) of thyroid cancer is uniformly solid or has minimal (1-5%) cystic change by sonography. Marked cystic change (>50% of the nodule) occurred in only 2.5% of cancers, which had other sonographic findings worrisome for malignancy.

The prognostic value of 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography in patients with suspected residual or recurrent medullary thyroid carcinoma

PURPOSE

To explore the prognostic value of 2-deoxy-2-[18F]fluoro-D-glucose (FDG) positron emission tomography (PET) in patients with suspected residual or recurrent medullary thyroid carcinoma (MTC).

PROCEDURES

This retrospective study included all patients with MTC examined with FDG-PET at Mayo Clinic, Rochester, Minnesota, from October 1999 to March 2008. The PET results were compared with other imaging studies and clinical findings, including carcinoembryonic antigen and calcitonin levels.

RESULTS

Twenty-nine patients with MTC were included. PET was positive in 14 patients, with follow-up information for 11; six died from metastatic disease, four had disease progression, and one remained in stable condition. PET was negative in 15 patients, with follow-up for 12; one had recurrent disease, and 11 had no evidence of clinical disease. Calcitonin doubling time was shorter for PET-positive than for PET-negative patients.

CONCLUSION

FDG-PET has high prognostic value in patients with suspected residual or recurrent MTC.

Need for a revised staging consensus in medullary thyroid carcinoma

HYPOTHESIS

Assessing prognosis for medullary thyroid cancer remains challenging and inexact. We hypothesize that the 1997 TNM staging criteria, especially for stage IV, are more accurate than the current 2002 staging system.

DESIGN

Retrospective cohort study.

SETTING

Tertiary referral center.

PATIENTS

One hundred seventy-three patients surgically treated for medullary thyroid cancer from January 1, 1980, to December 31, 2007.

MAIN OUTCOME MEASURES

Patients were staged according to 1997 and 2002 TNM criteria and according to treatment result: biochemically cured (normal calcitonin level); clinically cured (elevated calcitonin level but no evidence of disease by imaging); or not cured. Survival was calculated from initial surgery to death or last follow-up. Analysis used McNemar test to compare paired proportions and Kaplan-Meier estimation with log-rank tests.

RESULTS

A significantly higher proportion of patients were classified as having stage IV cancer using 2002 criteria compared with 1997 criteria (33% vs 7%, respectively; P < .001). Stage IV, 5-year overall survival was 82% (95% confidence interval, 72%-93%) with 2002 criteria vs 46% (95% confidence interval, 22%-93%) with 1997 criteria. Despite 15 of 36 clinically cured patients (42%) being classified as having stage IV cancer (13 patients with stage IVa cancer, 2 patients with stage IVb cancer) by the 2002 criteria, the observed overall survival of the clinically cured group at 5, 10, and 15 years was 100%, 100%, and 79%, respectively (P = .7 compared with those biochemically cured).

CONCLUSIONS

The current 2002 TNM staging for medullary thyroid cancer appears inadequate, especially for patients with stage IV cancer. Elevated but stable calcitonin levels often do not portend unfavorable outcome. Patients with lymph node metastases, irrespective of their location, but without distant disease would seem best classified as having stage III cancer.

Papillary thyroid microcarcinoma: a study of 900 cases observed in a 60-year period

BACKGROUND

The study aims were to characterize patients with papillary thyroid microcarcinoma (PTM) and to describe post-surgical outcome.

METHODS

Nine hundred PTM patients had initial treatment at Mayo Clinic during 1945-2004. Mean follow-up was 17.2 years. Recurrence and mortality details were derived from a computerized database.

RESULTS

Median tumor size was 7 mm; 98% were intrathyroidal. 273 patients (30%) had neck nodal involvement; 3 (0.3%) had distant metastases at diagnosis. Seven-hundred and sixty-five (85%) underwent bilateral lobar resection (BLR; total-, near-total, or bilateral subtotal thyroidectomy). Regional nodes were removed by either "node picking" (27%) or compartmental dissection (23%). Tumor resection was incomplete in 5 (0.6%). Radioiodine remnant ablation (RRA) was performed in 155 (17%). Overall survival did not differ from expected for an age and gender matched control group (P = .96); 3 patients (0.3%) died of PTM. None of the 892 patients with initial complete tumor resection developed metastatic spread during 20 postoperative years. Twenty-year and 40-year tumor recurrence rates were 6% and 8%, respectively. Higher recurrence rates were seen with multifocal tumors (P = .004) and node-positive patients (P < .001). Neither more extensive surgery nor RRA reduced recurrence rates compared to unilateral lobectomy.

CONCLUSION

More than 99% of PTM patients are not at risk of distant spread or cancer mortality. RRA after BLR did not improve postoperative outcome.

18F-FDG PET in the management of patients with anaplastic thyroid carcinoma

BACKGROUND

Anaplastic thyroid carcinoma (ATC) is one of the most aggressive solid tumors in humans. The use of positron emission tomography (PET) with 18F-fluorodeoxyglucose (18F-FDG) in ATC has not been studied, and only a few case reports have been published. The objective of this study was to investigate the potential contribution of 18F-FDG PET to the clinical management of patients with ATC.

METHODS

All patients with ATC studied with 18F-FDG PET from August 2001 through March 2007 were included. The PET results were correlated with computed tomography, ultrasound, magnetic resonance imaging, bone scan, histology, and clinical follow-up. The FDG uptake was semiquantified as maximum standard uptake value. Any change in the treatment plan as a direct result of the PET findings as documented in the clinical notes was recorded.

RESULTS

Sixteen patients were included. True-positive PET findings were seen for all primary tumors, in all nine patients with lymph node metastases, in five out of eight patients with lung metastases, and in two patients with distant metastases other than lung metastases. In 8 of the 16 patients, the medical records reported a direct impact of the PET findings on the clinical management.

CONCLUSIONS

ATC demonstrates intense uptake on 18F-FDG PET images. In 8 of the 16 patients (50%), the medical records reported a direct impact of the PET findings on the management of the patient. PET may improve disease detection and have an impact on the management of patients with ATC relative to other imaging modalities.

Management of patients with low-risk papillary thyroid carcinoma

OBJECTIVE

To define a rational, cost-effective, simple approach to managing most patients with papillary thyroid cancer (PTC) who are at low-risk of either cause-specific mortality or tumor recurrence.

METHODS

Taking advantage of the collective experience of a cohort of 2512 patients with PTC who had initial definitive treatment at the Mayo Clinic in Rochester, Minnesota, between 1940 and 2000, a 5-step approach to the management of low-risk PTC has been devised. This program is based on appropriate preoperative ultrasound localization of neck disease and potentially curative surgery consisting of near-total or total thyroidectomy, with appropriate neck nodal exploration and resection.

RESULTS

The emphasis of the present program is on the extent of initial surgery, where optimal care is ascribed to a near-total thyroidectomy with curative intent and appropriate neck nodal resection as predicated by appropriate preoperative ultrasonography evaluation of regional lymph nodes. Radioiodine remnant ablation (RRA) is not applicable to patients with PTC who are defined on the day of definitive initial surgery to be at low risk as defined by a metastasis, age, completeness of resection, invasion, and size (MACIS) score of less than 6.

CONCLUSION

The outlook for patients with low-risk PTC is very optimistic, with rates at 30 postoperative years of only 1% for cause-specific mortality and less than 15% for tumor recurrence at any site. The long-term results obtained by potentially curative bilateral resection, appropriate regional lymph nodal excision, and selective use of RRA are excellent. Realistically improving these acceptably low rates for cause-specific mortality and tumor recurrence may be difficult.

The value of quantifying 18F-FDG uptake in thyroid nodules found incidentally on whole-body PET–CT

OBJECTIVE

To determine if quantification of [18F]fluorodeoxyglucose (18F-FDG) uptake in a thyroid nodule found incidentally on whole-body 18F-FDG positron emission tomography-computed tomography (PET-CT) can be used to discriminate between malignant and benign aetiology.

METHODS

A retrospective review of all patients with focally high uptake in the thyroid as an incidental finding on 18F-FDG PET-CT from May 2003 through May 2006. The uptake in the nodules was quantified using the maximum standardized uptake value (SUVmax). The aetiology was determined by cytology and/or ultrasound, or on histopathology.

RESULTS

Incidental focally high uptake was found in 79/7347 patients (1.1%). In 31/48 patients with adequate follow-up, a benign aetiology was determined. Median SUVmax for the benign group was 5.6, range 2.5-53. Malignancy was confirmed in 15/48 patients. The malignancies were papillary thyroid carcinoma in 12, metastasis from squamous cell carcinoma in one, and lymphoma in two. Median SUVmax for the malignant lesions was 6.4, range 3.5-16. Cytology suspicious for follicular carcinoma was found in 2/48 patients. No statistical difference (P=0.12) was found among the SUVmax between the benign and malignant groups.

CONCLUSION

Focally high uptake of 18F-FDG in the thyroid as an incidental finding occurred in 1.1% of the patients. Malignancy was confirmed or was suspicious in 17/48 (35%) of the patients that had adequate follow-up. There was no significant difference in the SUVmax between benign and malignant nodules.

Management of Thyroid Nodules Detected at US

The Society of Radiologists in Ultrasound convened a panel of specialists from a variety of medical disciplines to come to a consensus on the management of thyroid nodules identified with thyroid ultrasonography (US), with particular focus on which nodules should be subjected to US-guided fine needle aspiration and which thyroid nodules need not be subjected to fine-needle aspiration. The panel met in Washington, DC, October 26-27, 2004, and created this consensus statement. The recommendations in this consensus statement, which are based on analysis of the current literature and common practice strategies, are thought to represent a reasonable approach to thyroid nodular disease.

Selective use of radioactive iodine in the postoperative management of patients with papillary and follicular thyroid carcinoma

Radioiodine remnant ablation (RRA) was developed in the 1960s to "complete a thyroidectomy" in the initial management of papillary and follicular thyroid cancer. By the 1990s, it was claimed that RRA diminished recurrence rates in follicular cell-derived cancer (FCDC) patients and decreased the cause-specific mortality (CSM) in patients more than 40 years old at initial surgery. The international trend for the past decade has been towards routine RRA in most FCDC patients. Clinical guidelines have been produced by many societies, promoting such an aggressive stance. Since 1997, many papers have reported improved outcome in FCDC, when patients were subjected to RRA after bilateral lobar resection. However, during the same time-period, it has been recognized that most FCDC patients are truly at "low-risk" of developing life-threatening recurrences. Accordingly, it has been suggested that rational therapy selection should lead to restricting aggressive therapy to those "high-risk" FCDC patients, more predisposed to CSM. To date, no prospective controlled trials exist. Presently available outcome data is based on single institutional or multicenter retrospective studies. This article summarizes the available relevant reported data, and concludes that a selective use of RRA in the postoperative management of FCDC patients is rational, and should actually be encouraged.

Value of preoperative ultrasonography in the surgical management of initial and reoperative papillary thyroid cancer

BACKGROUND

Cervical recurrences, predominantly in lymph nodes, occur in 14% to 30% of patients with papillary thyroid cancer (PTC). Postoperative surveillance for recurrent PTC increasingly includes thyrotropin-stimulated thyroglobulin and high-resolution ultrasonography (US). This combination commonly can detect recurrent disease as small as 5 mm.

HYPOTHESIS

Preoperative US will increase detection and assessment of the extent of lymph node metastasis (LNM) in patients with PTC.

DESIGN

Retrospective cohort study.

SETTING

Tertiary care academic center.

PATIENTS

From January 1, 1999, to December 31, 2004, a total of 770 patients were seen, 551 (381 female and 170 male; median age, 47 years; age range, 9-89 years) who underwent initial surgical management and 219 (154 female and 65 male; median age, 44 years; age range, 5-90 years) who underwent cervical reoperation for PTC. The US images were obtained preoperatively for 486 initial and 216 reoperative patients. Therapeutic radioactive iodine was administered to 151 (68.9%) of the reoperative patients before the subsequent operation (median dose, 5.6 x 10(9) Bq; range, 7.4 x 10(8)-3.7 x 10(10) Bq).

RESULTS

Ultrasonography identified nonpalpable lateral jugular LNMs in 70 (14.4%) of the patients undergoing initial exploration. Similarly, in reoperative patients, nonpalpable lateral LNMs were detected via US in 106 (64.2%), and 61 (28.2%) had LNMs detected in the central neck. Even when nodes were palpable preoperatively (37 [6.7%] of the initial and 56 [25.6%] of the reoperative patients), US assessment of the extent of LNM involvement altered the operation in 15 (40.5%) of the initial and 24 (42.9%) of the reoperative patients. The sensitivity, specificity, and positive predictive value for US were 83.5%, 97.7%, and 88.8% in initial patients, and 90.4%, 78.9%, and 93.9% in reoperative patients.

CONCLUSIONS

Overall, preoperative US detected nonpalpable LNMs in 231 (32.9%) of the 702 patients with PTC who underwent US, thereby altering the operative procedure performed. In addition, even in patients with palpable LNs, US helped to guide the extent of lymphadenectomy.

Management of thyroid nodules detected at US: Society of Radiologists in Ultrasound consensus conference statement

The Society of Radiologists in Ultrasound convened a panel of specialists from a variety of medical disciplines to come to a consensus on the management of thyroid nodules identified with thyroid ultrasonography (US), with particular focus on which nodules should be subjected to US-guided fine needle aspiration and which thyroid nodules need not be subjected to fine-needle aspiration. The panel met in Washington, DC, October 26-27, 2004, and created this consensus statement. The recommendations in this consensus statement, which are based on analysis of the current literature and common practice strategies, are thought to represent a reasonable approach to thyroid nodular disease.

[Papillary thyroid carcinoma: clinical manifestations, recurrences and prognosis]

Papillary carcinoma was detected in 2512 cases out of 3048 patients with differentiated thyroid carcinoma who underwent surgery during a 61-year period at the Mayo Clinic. The clinical picture of papillary carcinoma was shown to be interrelated with the appearance of recurrences, metastases and with prognosis for life. Lethality and survival were estimated within 5, 10, 20, 30 and 40 years depending on the stage of the disease that allowed a separation and comparison of groups of low and high risk in connection with the further prognosis. Median follow-up was 14 +/- 0.9 years and the longest follow-up was 60 years. It was shown that if the tumor was confined to the neck and the tumor was grossly resected the survival rate did not differ from the level predicted by an actuarial curve, and the appearance of metastases in regional lymph nodes represented no real threat in low-risk patients.

Sonography of Thyroid Nodules

This article describes an approach to some of the commonly encountered, "classic pattern," appearances of both benign and malignant thyroid nodules that are seen in day-to-day practice. These appearances include specific nodules that commonly need fine needle aspiration (FNA)/biopsy, and other nodules that do not usually need FNA/biopsy.

Long-term trends in thyroid carcinoma: a population-based study in Olmsted County, Minnesota, 1935-1999

OBJECTIVE

To determine whether there was a significant increase in the incidence of thyroid carcinoma in Olmsted County, Minnesota, that may be attributed to the widespread use of therapeutic head and neck irradiation between 1920 and the 1950s or to exposure to atomic fallout at the Nevada Test Site in the 1960s.

METHODS

Rochester Epidemiology Project resources were used to identify potential cases of thyroid carcinoma among residents of Olmsted County between 1935 and 1984. We extended this earlier study through 1999.

RESULTS

During the study period, thyroid carcinoma was newly diagnosed in 263 residents. In women, the age-adjusted incidence increased from 2.7 per 100,000 person-years (p-y) in 1935-1949 to 9.2 per 100,000 p-y in 1990-1999 (P = .001); In men, the rate increased from 0.8 to 5.0 per 100,000 p-y (P = .007). However, most of the increase occurred before 1965 and remained relatively stable thereafter. Similar trends were observed for papillary carcinoma alone.

CONCLUSION

Although the Incidence of thyroid carcinoma increased significantly between 1935 and 1964, no significant Increases have been seen since 1965, suggesting that neither atmospheric atomic fallout from the Nevada Test Site nor use of ionizing radiation to treat conditions of the head and neck significantly affected the incidence of thyroid carcinoma in Olmsted County.

PPARgamma staining as a surrogate for PAX8/PPARgamma fusion oncogene expression in follicular neoplasms: clinicopathological correlation and histopathological diagnostic value

The PAX8/PPARgamma (PPFP) fusion-oncogene is moderately specific for follicular thyroid carcinomas (FTC). It remains unknown whether this can be translated into improved diagnosis, classification, or outcome prediction. We studied a cohort of well-characterized follicular adenomas (FA), FTC, and Hurthle cell carcinomas (HCC) from patients with complete clinical follow-up, to determine whether PPARgamma immunohistochemistry (as a surrogate of PAX8/PPARgamma expression) helps to distinguish FA from FTC and to assess its diagnostic accuracy as an adjunct to frozen section. We also correlated PPARgamma staining with clinical outcomes to assess its role as a prognostic marker.PPARgamma staining was more common in FTC (31 of 54; 57%) than in HCC (one of 23; 4%) or FA (four of 31; 13%) (P < 0.000001). Adjunctive use of PPARgamma immunohistochemistry improved diagnostic sensitivity of intraoperative frozen section from 84% to 96% (P < 0.05) but reduced specificity from 100% to 90% (P < 0.05). PPARgamma staining was associated with favorable prognostic indicators (female gender, better tumor differentiation, and lesser risk of metastases).PPARgamma staining may be helpful in the differential diagnosis of FA, FTC, and HCC, particularly when diagnostic sensitivity of histomorphology is reduced (e.g. during intraoperative frozen section). PPARgamma staining also shows an association with favorable prognosis and may have a role in risk stratification.

Current Strategies for Surgical Management and Adjuvant Treatment of Childhood Papillary Thyroid Carcinoma

Childhood papillary thyroid carcinoma is associated with more locally aggressive and more frequent distant disease than its adult counterpart. Recurrence rates tend to be higher in children, but cause-specific mortality remains low. Optimal initial treatment of childhood papillary thyroid carcinoma should include total or near-total thyroidectomy and central compartment node clearance. Modified neck dissections should be performed for biopsy-proven lateral neck disease. Every effort should be made to maintain parathyroid and laryngeal nerve function. Radical neck dissections are to be avoided. Radioiodine remnant ablation (RRA), appropriate thyroid hormone suppressive therapy (THST), and judicious use of therapeutic doses of (131)I are applied to achieve a disease-free status, which is most often confirmed by negative neck ultrasonography, negative whole-body scan (either withdrawal or recombinant human thyroid-stimulating hormone-stimulated), and extremely low levels of serum thyroglobulin. Appropriate utilization of (131)I, THST, repeat surgery, external beam radiotherapy, and rarely chemotherapy may provide long-term palliation and some cures in patients with recurrent/persistent disease. Follow-up should be lifelong, and the care of children after age 17 should subsequently be transferred to adult-care endocrinologists with expertise in managing thyroid neoplasia. Optimal surgical management can be achieved if adequate operations are routinely carried out by "high-volume" thyroid surgeons with expertise in the care of children. Nowhere is a multidisciplinary approach (endocrinologists, surgeons, nuclear medicine physicians, pediatricians, pathologists, oncologists) more critical than in the long-term management of papillary thyroid carcinoma that presents during childhood.

The PAX8/PPARγ fusion oncoprotein transforms immortalized human thyrocytes through a mechanism probably involving wild-type PPARγ inhibition

Follicular thyroid carcinoma (FTC) frequently harbors the PAX8/PPARgamma fusion gene (PPFP); however, its oncogenic role and mechanism(s) of action remain undefined. We investigated PPFP's effects on cell growth, apoptosis, cell-cell, and cell-matrix interactions in immortalized human thyroid cells (Nthy-ori 3-1) and NIH 3T3 cells. PPFP expression increased the growth of transient and stable Nthy-ori transfectants ( approximately threefold by 72 h). There was an 8.4% increase of cells in the S+G2/M phase, a 7.8% decrease in cells in the G0+G1 phase and a 66% decline in apoptosis at 72 h. Stable Nthy-ori PPFP transfectants grew in soft agar, and PPFP-transfected NIH 3T3 cells exhibited efficient focus formation, suggesting loss of anchorage-dependent growth and contact inhibition, respectively. Overexpression of PPARgamma in Nthy-ori cells did not recapitulate PPFP's growth effects. Treatment of Nthy-ori cells with an irreversible PPARgamma inhibitor mimicked the growth-promoting effects of PPFP and co-expression of PPFP and PPARgamma blocked PPARgamma transactivation activity. Our data provide functional evidence that PPFP acts as an oncoprotein, whose transforming properties depend in part on inhibition of PPARgamma. Our data suggest that PPFP contributes to malignant transformation during FTC oncogenesis by acting on several cellular pathways, at least some of which are normally regulated by PPARgamma.

18F-FDG PET of patients with Hürthle cell carcinoma

Hürthle cell carcinoma is an uncommon differentiated thyroid cancer characterized by an aggressive clinical course and low avidity for (131)I. Treatment usually involves an aggressive surgical approach often combined with (131)I. (18)F-FDG PET has been helpful in the staging and evaluation of many types of aggressive malignancy. No reports to date have described the utility of PET in a series of patients with Hürthle cell cancer. We reviewed our experience with (18)F-FDG PET in the care of patients with Hürthle cell carcinoma to determine the likelihood of uptake in these cancers and the effect of (18)F-FDG PET on patient care.

METHODS

Patients with Hürthle cell cancer who were seen between June 2000 and April 2002 and were imaged with (18)F-FDG PET were included. Imaging and clinical data were reviewed. PET results were compared with the results of anatomic imaging (CT, sonography, or MRI) and (131)I imaging when performed. Patient charts were reviewed to identify any change in management that resulted from the (18)F-FDG PET findings.

RESULTS

Fourteen (18)F-FDG PET scans of 12 patients were obtained in the time frame indicated. All patients had documented Hürthle cell carcinoma. PET showed intense (18)F-FDG uptake in all known Hürthle cell cancer lesions but one. PET showed disease not identified by other imaging methods in 7 of the 14 PET scans. PET identified distant metastatic disease (5) or local disease (2) that was more extensive than otherwise demonstrated. In 7 of the 14 scans, the information provided by PET was used to guide or change therapy.

CONCLUSION

Hürthle cell carcinoma demonstrates intense uptake on (18)F-FDG PET images. PET improves disease detection and disease management in patients with Hürthle cell carcinoma relative to anatomic or iodine imaging. (18)F-FDG PET should be recommended for the evaluation and clinical management of patients with Hürthle cell carcinoma.