Impact of central node dissection on postoperative morbidity in pediatric patients with suspected or proven thyroid cancer

Role of prophylactic central neck lymph node dissection for papillary thyroid carcinoma in the era of de-escalation

Thyroid cancer is the most common endocrine malignancy. While there has been no appreciable increase in the observed mortality of well-differentiated thyroid cancer, there has been an overall rise in its incidence worldwide over the last few decades. Patients with papillary thyroid carcinoma (PTC) and clinical evidence of central (cN1) and/or lateral lymph node metastases require total thyroidectomy plus central and/or lateral neck dissection as the initial surgical treatment. Nodal status in PTC patients plays a crucial role in the prognostic evaluation of the recurrence risk. The 2015 guidelines of the American Thyroid Association (ATA) have more accurately determined the indications for therapeutic central and lateral lymph node dissection. However, prophylactic central neck lymph node dissection (pCND) in negative lymph node (cN0) PTC patients is controversial, as the 2009 ATA guidelines recommended that CND "should be considered" routinely in patients who underwent total thyroidectomy for PTC. Although the current guidelines show clear indications for therapeutic CND, the role of pCND in cN0 patients with PTC is still debated. In small solitary papillary carcinoma (T1, T2), pCND is not recommended unless there are high-risk prediction factors for recurrence and diffuse nodal spread (extrathyroid extension, mutation in the BRAF gene). pCND can be considered in cN0 disease with advanced primary tumors (T3 or T4) or clinical lateral neck disease (cN1b) or for staging and treatment planning purposes. The role of the preoperative evaluation is fund-amental to minimizing the possible detrimental effect of overtreatment of the types of patients who are associated with low disease-related morbidity and mortality. On the other hand, it determines the choice of appropriate treatment and determines if close monitoring of patients at a higher risk is needed. Thus, pCND is currently recommended for T3 and T4 tumors but not for T1 and T2 tumors without high-risk prediction factors of recurrence.

Medullary thyroid carcinoma

INTRODUCTION

Medullary thyroid carcinoma (MTC) constitutes approximately 5-10% of all thyroid cancers. Although the tumor forms in the thyroid, it doesn't originate from thyroid cells, but from the C cells or parafollicular cells which produce and release a hormone called calcitonin (CT). Starting from the second half of the 1900s, MTC was progressively studied and defined.

AREAS COVERED

This study aims to analyze the history, clinical presentation and biological behavior of MTC, bio-humoral and instrumental diagnosis, molecular profiling, genetic screening, preoperative staging and instrumental procedures, indispensable in expert and dedicated hands, such as high-resolution ultrasonography, CT-scan, MRI and PET/TC. We examine recommended and controversial surgical indications and procedures, prophylactic early surgery and multiple endocrine neoplasia surgery. Also, we discuss pathological anatomy classification and targeted therapies. The role of serum CT is valued both as undisputed and constant preoperative diagnostic marker, obscuring cytology and as early postoperative marker that predicts disease persistence.

EXPERT OPINION

With a complete preoperative study, unnecessary or useless, late and extended interventions can be reduced in favor of tailored surgery that also considers quality of life. Finally, great progress has been made in targeted therapy, with favorable impact on survival.

Prophylactic and Early Thyroidectomy in RET Germline Mutation Carriers in Pediatric and Adult Population: Long-Term Outcomes of a Series of 63 Patients

Prophylactic and early thyroidectomy in RET germline mutation carriers allows the removal of the thyroid before medullary thyroid carcinoma (MTC) develops, or while it is still confined to the gland. This study was aimed to assess the clinicopathological features in RET carriers according to the age at surgery and the long-term outcomes after prophylactic and early thyroidectomy. A retrospective analysis of 63 operated asymptomatic RET carriers diagnosed after familial genetic screening was performed. Twenty-one RET carriers were operated at pediatric (<18 yrs) and 42 at adult (≥18 yrs) age. Serum preoperative calcitonin levels were significantly lower in pediatric compared to adult patients (p = 0.04); moreover, adult RET carriers had a greater frequency of microMTC at pathology (p = 0.009). Permanent postoperative morbidity occurred in 9.5% of patients, without differences between the two groups. Biochemical postoperative cure was achieved in all patients. At a median follow-up of 14 years, all C-cell hyperplasia patients are disease-free; conversely, biochemical, and structural recurrence of disease occurred in three adults and one pediatric patient with microMTC. The independent predictive factors of MTC were the age at surgery, the preoperative calcitonin level and the RET mutational risk profile (p < 0.02). In conclusion, prophylactic and early thyroidectomy are safe and effective procedures in achieving definitive cure in most RET carriers. However, since recurrences may occur at long-term in case of microMTC, thyroidectomy should be possibly performed earlier to prevent microMTC development.

Incidental Parathyroidectomy Among Pediatric Patients Undergoing Thyroid Surgery

OBJECTIVE

To evaluate rates of incidental parathyroidectomy(IP) and to determine risk factors among children undergoing thyroid surgery.

STUDY DESIGN

Retrospective case-control study.

METHODS

Pediatric patients undergoing thyroidectomy with or without neck dissection were included in this retrospective cohort study over a 20 year period. Demographics, clinical features, and surgical outcomes were evaluated. The primary outcome was the presence of parathyroid tissue in the surgical specimen.

RESULTS

Two hundred and eighty-six patients were included (100 cases with ≥1 parathyroid gland found in the pathology specimen and 186 controls). The most common surgical indication was cancer (49%), followed by benign nodule (25%). Hemithyroidectomy was performed in 119 (42%) patients, total thyroidectomy in 138 (48%), and completion in 29 (10%). Central neck dissection (CND) and lateral neck dissection were performed in 41% and 13%, respectively. 27 (9%) patients had parathyroid reimplantation. On univariable analysis, diagnosis, adenopathy on preoperative ultrasound, extent of thyroidectomy, neck dissection, and parathyroid reimplantation were significant predictors of IP. On multivariate analysis, CND > 5 nodes were the sole predictor of IP. Patients with IP were more likely to require postoperative calcium/vitamin D supplementation compared to those without (44% vs. 16%; P < .001).

CONCLUSIONS

Incidental parathyroidectomy during pediatric thyroidectomy is relatively common. CND was independently predictive of IP. There were increased rates of postoperative hypocalcemia when 1 or more parathyroid gland was identified in the specimen. Reimplantation of 1 parathyroid gland was predictive of another gland in the specimen. Anticipating outcomes may help optimize patient care by allowing for early supplementation, frequent monitoring, and consideration of ancillary monitoring modalities in high-risk procedures.

LEVEL OF EVIDENCE

Level 4 Laryngoscope, 132:2262-2269, 2022.

Paediatric differentiated thyroid carcinoma: a UK National Clinical Practice Consensus Guideline

This guideline is written as a reference document for clinicians presented with the challenge of managing paediatric patients with differentiated thyroid carcinoma up to the age of 19 years. Care of paediatric patients with differentiated thyroid carcinoma differs in key aspects from that of adults, and there have been several recent developments in the care pathways for this condition; this guideline has sought to identify and attend to these areas. It addresses the presentation, clinical assessment, diagnosis, management (both surgical and medical), genetic counselling, follow-up and prognosis of affected patients. The guideline development group formed of a multi-disciplinary panel of sub-speciality experts carried out a systematic primary literature review and Delphi Consensus exercise. The guideline was developed in accordance with The Appraisal of Guidelines Research and Evaluation Instrument II criteria, with input from stakeholders including charities and patient groups. Based on scientific evidence and expert opinion, 58 recommendations have been collected to produce a clear, pragmatic set of management guidelines. It is intended as an evidence base for future optimal management and to improve the quality of clinical care of paediatric patients with differentiated thyroid carcinoma.

Development and validation of a population-based model for predicting the regional lymph node metastasis in adolescent differentiated thyroid carcinoma

BACKGROUND

Adolescent differentiated thyroid carcinoma (DTC) is a rare type of thyroid cancer that represents a special entity of all endocrine-related cancer. This study aims to establish the first nomogram for predicting the regional (central and lateral) lymph node metastasis (LNM) in the adolescent population for better surgical management.

METHOD

We retrospectively reviewed the clinicopathology characteristics of adolescent patients with DTC in the Surveillance, Epidemiology, and End Results database between 2010 and 2015.

RESULTS

A total of 1,930 adolescent patients between the ages of 10 and 24 years from the SEER database were enrolled in this study. Six predictive factors including age, race, histology, multifocality, extrathyroidal invasion (EI) and tumor size were identified to be significantly associated with the regional LNM via univariate and multivariate logistic regression analyses. These indicators were used to construct a nomogram for predicting the regional LNM in adolescent patients with DTC. Moreover, a satisfied predictive ability of the model was determined with a C-index of 0.794, supported by an internal validation group with a C-index of 0.776. The Decision Curve Analysis and calibration curve further conducted a great agreement in our model.

CONCLUSION

The first predictive model containing multiple factors has been successfully established with good discrimination for predicting the regional LNM in adolescent patients with DTC. This nomogram could effectively help surgeons to make better individualized surgical decision intraoperatively, especially in terms of whether cervical lymph node dissection (LND) is warranted.

Recurrent Laryngeal Nerve Preservation Strategies in Pediatric Thyroid Oncology: Continuous vs. Intermittent Nerve Monitoring

Simple Summary

Thyroid operations in children are difficult because children have thinner nerves than adults, and there is less space for the surgeon to operate. Since it runs closely behind the thyroid capsule, the nerve innervating the vocal cords can be injured during the operation. In thyroid cancer, the thyroid gland typically needs to be removed completely, putting the nerve at greater risk of injury. This surgical risk can be reduced by monitoring the function of the nerve before it is lastingly damaged. There are two methods to achieve this: intermittent (longer intervals between pulses) and continuous (very small intervals between pulses) nerve stimulation. In this study of 258 children with suspected or confirmed thyroid cancer, nerve damage and vocal cord palsy were observed only after intermittent and not after continuous nerve stimulation. This demonstrated that continuous nerve stimulation was safer than intermittent nerve stimulation.

Abstract

(1) Background: Pediatric thyroidectomy is characterized by considerable space constraints, thinner nerves, a large thymus, and enlarged neck nodes, compromising surgical exposure. Given these challenges, risk-reduction surgery is of paramount importance in children, and even more so in pediatric thyroid oncology. (2) Methods: Children aged ≤18 years who underwent thyroidectomy with or without central node dissection for suspected or proven thyroid cancer were evaluated regarding suitability of intermittent vs. continuous intraoperative neuromonitoring (IONM) for prevention of postoperative vocal cord palsy. (3) Results: There were 258 children for analysis, 170 girls and 88 boys, with 486 recurrent laryngeal nerves at risk (NAR). Altogether, loss of signal occurred in 2.9% (14 NAR), resulting in six early postoperative vocal cord palsies, one of which became permanent. Loss of signal (3.5 vs. 0%), early (1.5 vs. 0%), and permanent (0.3 vs. 0%) postoperative vocal cord palsies occurred exclusively with intermittent IONM. With continuous nerve stimulation, sensitivity, specificity, positive and negative predictive values, and accuracy reached 100% for prediction of early and permanent postoperative vocal cord palsy. With intermittent nerve stimulation, sensitivity, specificity, positive and negative predictive values, and accuracy were consistently lower for prediction of early and permanent postoperative vocal cord palsy, ranging from 78.6% to 99.8%, and much lower (54.2–57.9%) for sensitivity. (4) Conclusions: Within the limitations of the study, continuous IONM, which is feasible in children ≥3 years, was superior to intermittent IONM in preventing early and permanent postoperative vocal cord palsy.

Prophylactic Central Neck Dissection in Well-differentiated Thyroid Cancer

Well-differentiated cancers, both papillary and follicular, account for 90% of all diagnosed thyroid cancers. They have an indolent disease course with a 20-year disease-specific survival over 90%. According to current guidelines, the therapy of choice for well-differentiated thyroid carcinoma is total thyroidectomy or lobectomy. The indication for prophylactic central neck dissection is still a controversial issue and the subject of unfinished and ongoing debate. There is no indication for prophylactic central neck dissection in follicular thyroid carcinomas, which primarily metastasize hematogenously. In small solitary papillary thyroid carcinomas (T1 and T2), prophylactic central neck dissection is not indicated as it does not bring benefits in terms of improved patient survival and at the same time significantly increases the risk of temporary and permanent postoperative complications. Prophylactic central neck dissection is indicated in advanced papillary thyroid cancers (T3 and T4) and all other high-risk well-differentiated thyroid cancer, as well as in the presence of metastatic lymph nodes in the lateral neck.

Risk factors for the development of hypocalcemia in pediatric patients after total thyroidectomy - A systematic review

OBJECTIVES

Post-thyroidectomy hypocalcemia is a common complication that causes increased morbidity. This review aims to identify the factors that predict occurrence of hypocalcemia after total thyroidectomy in children and adolescents.

METHODS

Comprehensive searches of English language pediatric (≤18 years of age) articles were performed in Medline, CINAHL, EMBASE, Web of Science and the Cochrane Library. Studies published between January 1, 1970 to August 20, 2020 regarding risk factors and strategies to prevent hypocalcemia were included if the study: 1. included only pediatric patients who were ≤18 years of age, 2. included only patients who had total, subtotal or completion thyroidectomy, 3. defined hypocalcemia as serum total calcium of <2.0 mmol/L (8 mg/dL) or ionized calcium of <1.0 mmol/L. The quality of included papers was assessed using the Newcastle-Ottawa scale. Results of all included studies were summarised. Meta-analyses were performed if appropriate.

RESULTS

Five studies with a total of 477 patients between 0 and 18 years, who had total/subtotal/completion thyroidectomy, were included. Overall rates of transient hypocalcemia were higher than permanent hypocalcemia (transient n = 104, 22%; permanent n = 48, 10%). Two studies found intraoperative parathyroid hormone (PTH) useful in predicting hypocalcemia. While two single institution cohort studies reported that neck dissection, male sex and a lower Parathyroid Gland Remaining In Situ score were associated with hypocalcemia, two other studies, including one population-based cohort study, reported that age at surgery, patient sex, hospital volume, type of thyroid disease, number of identified parathyroid glands, parathyroid auto-transplantation, operation time, thyroid specimen weight, and lymph node dissection were not risk factors for hypocalcemia.

CONCLUSION

Intraoperative PTH may be useful in predicting hypocalcemia in children after total thyroidectomy. No consistent clinical risk factors or preventative methods were identified in the pediatric literature. High-quality pediatric research is urgently required to address this knowledge gap.

Role of intraoperative recurrent laryngeal nerve monitoring for pediatric thyroid surgery: Comparative analysis

BACKGROUND

The data on the advantages of intraoperative nerve monitoring (IONM) during pediatric thyroid surgeries are limited. We aimed to study the role of IONM by comparing between children who underwent thyroid surgery with and without IONM.

METHODS

A retrospective study of all children who underwent thyroid surgery between 2001 and 2019.

RESULTS

The study included 113 patients with 183 recurrent laryngeal nerve (RLN) at risk. Transient paralysis rate was more than 5-fold lower in the IONM group compared to the control group (1.5% vs 8%; P = .114). Permanent paralysis was documented only in the control group (2.5% vs 0%; P = .552). Children <10 years and those who underwent central neck dissection had significantly higher rates of RLN injury.

CONCLUSIONS

IONM was associated with decreased rate of RLN injury during pediatric thyroid surgery and should be considered especially in children under 10 years of age and those undergoing concomitant central neck dissection.

4-Hour postoperative PTH level predicts hypocalcemia after thyroidectomy in children

BACKGROUND

Hypocalcemia occurs frequently after a total thyroidectomy in pediatric patients. Four hour postoperative PTH monitoring predicts the need for calcium supplementation in the adult thyroidectomy population. We evaluated the role of the 4 h postoperative PTH level in determining the need for calcium supplementation after thyroidectomy in the pediatric population.

METHODS

This is a retrospective review of children undergoing total thyroidectomy by a single pediatric surgeon from July 2011 through July 2018. Intact PTH obtained four hours postoperatively determined the need for calcium supplementation for patients beginning in November 2014 onward. Serum total calcium levels were monitored concurrently with serum intact PTH levels. Serum calcium levels were followed in our Multispecialty Pediatric Endocrine Surgery clinic within the month following thyroidectomy.

RESULTS

From July 2011 through July 2018, there were a total of 56 total thyroidectomies at our institution. Prior to November 2014, all pediatric total thyroidectomies received calcium supplementation per our institutional protocol. Based on ionized calcium levels, 26.3% (5/19) of children developed hypocalcemia. From November 2014 to July 2018, 37 pediatric patients required total thyroidectomies. 29.7% (11/37) had low 4-h postoperative PTH levels. 72.7% (8/11) patients with low 4-h postoperative PTH levels had corresponding postoperative day 1 total calcium levels less than 8.5 or ionized calcium levels less than 1.12, and five children (45.5%) developed symptomatic hypocalcemia. 70% (26/37) of children had normal 4-h postop PTH levels, with only 5 (19%) ever developing hypocalcemia. No patients with a normal postop PTH level developed symptomatic hypocalcemia or required IV calcium repletion. A single 4-h postoperative PTH <10 pg/dl for identifying hypocalcemia has a sensitivity of 81% and specificity of 91%, with AUC 0.81.

CONCLUSION

The 4-h postoperative serum PTH level can help determine the need for calcium supplementation in pediatric patients undergoing total thyroidectomy, thereby reducing unnecessary calcium supplementation and serial lab draws to monitor for postoperative hypocalcemia.

LEVEL OF EVIDENCE

Level II.

Extrathyroidal Extension is an Important Predictor of Regional Lymph Node Metastasis in Pediatric Differentiated Thyroid Cancer

Introduction: The American Joint Committee Cancer (AJCC) TNM system predicts survival in patients with differentiated thyroid cancer (DTC). In the eighth edition of the AJCC TNM, microscopic extrathyroidal extension (microETE) was removed and tumor size >4 cm was maintained in the definition of T3 disease to reduce unnecessarily aggressive therapy for adults at low risk of death from DTC. In pediatric patients where DTC survival rates are high, the AJCC TNM is used to identify patients at increased risk of persistent, postsurgical disease, to identify patients who benefit from radioactive iodine therapy. The aim of this study was to assess the correlation of microETE with cervical lymph node (LN) metastasis in pediatric patients and to determine if tumor size or microETE is more informative in predicting regional LN disease. Methods: Patients with DTC <19 years of age at the time of thyroidectomy with AJCC T3 tumors (seventh edition) and the presence of LNs on the surgical specimen were included in this retrospective chart review. Pathological findings were confirmed by pathologist review. Results: Forty-five patients with AJCC T3 designation were included, 34 with microETE and 11 without microETE. Of those with microETE, 32 (94.1%) demonstrated regional LN metastasis compared with 5/11 patients (45.5%) without microETE (p = 0.001). In addition, microETE was associated with lateral neck LN metastasis (p = 0.004), bilateral disease (p = 0.001), and tumor multifocality (p = 0.003). Patients with microETE had smaller tumors (median = 2.5 cm, interquartile range [IQR]: 1.6-4.5) compared with patients without microETE (median = 5 cm, IQR: 4.2-5.4; p = 0.02). No increased association was found between microETE and vascular invasion, distant metastasis, or persistent/recurrent disease. Conclusions: In pediatric patients with DTC, microETE is a strong predictor of LN metastasis when compared with tumor size. For patients who do not undergo prophylactic central neck LN dissection, the presence of microETE predicts an increased risk of postsurgical disease and should be included in future revisions of the American Thyroid Association pediatric risk stratification categories.

Postoperative Hypoparathyroidism After Total Thyroidectomy in Children

BACKGROUND

Postoperative hypocalcemia because of hypoparathyroidism is the most common complication of total thyroidectomy in children. We hypothesized that most children with postoperative hypocalcemia would be eucalcemic by 12 mo and sought to define risk factors for permanent hypoparathyroidism.

METHODS

We retrospectively reviewed children who underwent total thyroidectomy at a single children's hospital from 2012 to 2019. Patients with prior neck surgery were excluded. Indication for operation, final pathologic diagnosis, and postoperative serum calcium up to 12 mo were recorded. Permanent hypoparathyroidism was defined as supplemental calcium requirement beyond 1 y postoperatively.

RESULTS

Sixty-eight patients underwent total thyroidectomy. Graves' disease was the most common benign indication for surgery (38 patients). Twenty-six patients (38%) had cancer on final pathology. Central lymph node dissection (CLND) was performed in 12 cancer patients. Twenty-eight patients (41%) had postoperative hypocalcemia. Eight patients (12%) had hypocalcemia at 6 mo. Risk factors for hypoparathyroidism at 6 mo were a cancer diagnosis (odds ratio [OR] 6.7; P = 0.02), CLND (OR 12.6; P < 0.01), and parathyroid tissue in the surgical specimen on pathologic analysis (OR 19.5; P < 0.01). Only two patients (3%) developed permanent hypoparathyroidism, both of whom had thyroidectomy for cancer and underwent CLND.

CONCLUSIONS

Children with thyroid cancer are at high risk for postoperative hypocalcemia after total thyroidectomy. The risk is further increased by CLND, which should be performed selectively. A majority of patients with hypoparathyroidism at 6 mo postoperatively regain normal parathyroid function by 1 y. Permanent hypoparathyroidism in children after total thyroidectomy at a pediatric endocrine surgery center is rare.

Risks of Hypoparathyroidism After Total Thyroidectomy in Children: A 21-Year Experience in a High-Volume Cancer Center

BACKGROUND

Hypoparathyroidism occurs relatively frequently after thyroid surgery in children. However, few studies have reported risk factors. We aimed to identify risk factors for hypoparathyroidism that occurred after total thyroidectomy for proven or suspected malignancy in children.

METHODS

Children (aged ≤ 18 years) who underwent total thyroidectomy for neoplasm or RET germline mutation at our institution between 1997 and 2018 were included. We retrospectively reviewed demographics, surgical indications, perioperative and follow-up laboratory results, pathologic results, and duration of calcium/calcitriol supplementation. Risk factors for hypoparathyroidism were identified by multivariate analysis.

RESULTS

Of 184 consecutive patients, 111 had undergone surgery for neoplasm; these diseases were primarily malignancies (106, 95.5%), predominantly papillary carcinoma (103, 92.8%). The remaining 73 patients had undergone early thyroidectomy for RET germline mutation. Among all patients, 67 (36.4%) had hypoparathyroidism: 61 transient and 6 permanent. In a multivariate analysis, central neck dissection (odds ratio 4.3, 95% confidence interval 2.0-9.1) and gross extrathyroidal extension (odds ratio 4.9, 95% confidence interval 2.0-12.1) predicted overall hypoparathyroidism; however, no significant factors were associated with permanent hypoparathyroidism. Most patients with permanent hypoparathyroidism (5 of 6) had undergone therapeutic central neck dissection. When central neck dissection was performed, younger children had a higher risk of overall hypoparathyroidism.

CONCLUSIONS

In pediatric total thyroidectomies, central neck dissection and gross extrathyroidal extension were major predictors for overall hypoparathyroidism. Surgeons performing thyroidectomy in such patients should be aware of the relatively high risk, preserve parathyroid tissue to the extent possible, and be conscientious regarding postoperative calcium monitoring and replacement.

Recurrence and Complications in Pediatric and Adolescent Papillary Thyroid Cancer in a High-Volume Practice

BACKGROUND

Treatment approaches for pediatric papillary thyroid cancer (PTC) are historically extrapolated from adult experience. However, pediatric PTC demonstrates a greater propensity for lymph node involvement, early metastases, and recurrence, highlighting the need for pediatric-specific treatment paradigms.

MATERIALS AND METHODS

A retrospective review included patients with PTC aged ≤21 y, with ≥18 mo of follow-up, treated between 2002 and 2015. Fisher's exact test and Cox proportional hazard were used to estimate the effect of risk factors on disease recurrence.

RESULTS

Seventy-two cases of PTC were identified with median age of 17.0 y and median follow-up of 64.1 mo. Disease recurred at a median of 24.6 mo (range 7.8-78.1) in 7 of 51 (13.7%) of patients with disease limited to the thyroid or central neck, 7 of 18 (39%) patients with lateral neck disease at presentation who underwent a compartment-based resection, and three of three patients (100%) with lateral neck disease who sought care after non-compartment-based resection. There were no deaths from disease. Univariate predictors of recurrence included tumor size >2 cm (P = 0.005), lateral neck disease (P = 0.004), lymphovascular invasion (P = 0.017), extracapsular invasion (P < 0.0001), multifocality (P = 0.03), and non-Caucasian race (P = 0.05). Multivariate analysis identified race (P = 0.05) as an independent predictor of recurrence. In patients without lateral neck disease, there was a trend toward lower recurrence in patients undergoing thyroidectomy with central neck dissection compared with thyroidectomy alone (P = 0.07).

CONCLUSIONS

Pediatric PTC is associated with excellent survival, although recurrence is common in patients with lateral node involvement. Predictors of recurrence are multifactorial and may be influenced by extent of disease, patient or tumor biology, and aggressiveness of resection.

LEVEL OF EVIDENCE

Prognosis study, level IV, retrospective case series.

5P Strategies for Management of Multiple Endocrine Neoplasia Type 2: A Paradigm of Precision Medicine

Multiple endocrine neoplasia type 2 (MEN2) is a neuroendocrine cancer syndrome characterized by medullary thyroid carcinoma, in combination or not with pheochromocytoma, hyperparathyroidism, and extra-endocrine features. MEN2 syndrome includes two clinically distinct forms subtyped as MEN2A and MEN2B. Nearly all MEN2 cases are caused by germline mutations of the RET proto-oncogene. In this review, we propose "5P" strategies for management of MEN2: prevention, prediction, personalization, psychological support, and participation, which could effectively improve clinical outcomes of patients. Based on RET mutations, MEN2 could be prevented through prenatal diagnosis or preimplantation genetic testing. Identification of pathogenic mutations in RET can enable early diagnosis of MEN2. Combining RET mutation testing with measurement of serum calcitonin, plasma or urinary metanephrine/normetanephrine, and serum parathyroid hormone levels could allow risk stratification and accurately prediction of MEN2 progression, thus facilitating implementation of personalized precision treatments to increase disease-free survival and overall survival. Furthermore, increased awareness of MEN2 is needed, which requires participation of physicians, patients, family members, and related organizations. Psychological support is also important for patients with MEN2 to promote comprehensive management of MEN2 symptoms. The "5P" strategies for management of MEN2 represent a typical clinical example of precision medicine. These strategies could effectively improve the health of MEN2 patient, and avoid adverse outcomes, including death and major morbidity, from MEN2.

Factors affecting the approaches and complications of surgery in childhood papillary thyroid carcinomas

BACKGROUND

The aim of the study is to analyse the factors related to permanent surgical complications in children and adolescents with papillary thyroid carcinoma treated by total thyroidectomy with central and bilateral neck dissections.

METHODS

Children and adolescents aged ≤18-year-old at presentation with papillary thyroid carcinoma during the years 1988-2010 underwent thyroid and lymph-node surgeries (with a median follow-up of 19.6 years) were analysed for post-surgical complications.

RESULTS

Permanent surgical morbidity occurred in 14% (n = 70) of patients who underwent total thyroidectomy as well as bilateral central and lateral neck dissections (n = 509). Factors associated with permanent complications included pN1 with extra-nodal extension, > 4 metastatic lymph nodes in the central neck compartment, presence of distant metastases and younger age of patients at surgery. Patients who received extensive surgery had better relapse-free survival rates (p < 0.001).

CONCLUSION

Total thyroidectomy and bilateral central as well as lateral neck dissections for children and adolescents with papillary thyroid carcinoma was associated with substantial postoperative complications. Nevertheless, it is associated with better prognosis for young patients with thyroid cancer. Prophylactic compartment-oriented lymph node dissections to these patients could be the management protocol in experienced hands.

Present status of prophylactic thyroidectomy in pediatric multiple endocrine neoplasia 2: a nationwide survey in Japan 1997-2017

Background In Japan, prophylactic thyroidectomy involves out-of-pocket expense. The American Thyroid Association (ATA) recommends prophylactic thyroidectomy for medullary thyroid carcinoma (MTC) during early childhood in patients with multiple endocrine neoplasia type 2 (MEN2). The ATA reports a high frequency of postoperative complications in childhood, which also influenced the delay of prophylactic thyroidectomy in Japan. Methods This retrospective study of multiple medical centers in Japan included individuals aged <20 years diagnosed with germline RET mutations between 1997 and 2017. The onset and onset possibility were defined based on confirmed lesions or calcitonin levels. The definition of risk and prophylactic thyroidectomy were based on the ATA 2015 revised guideline. Results Twenty-one patients with MEN2 were enrolled (highest risk, n = 5; high risk, n = 5; and moderate risk, n = 11). The cumulative incidence of the onset/onset possibility reached 50% at 5 and 8 years and 100% at 9 years and 17 years in high- and moderate-risk patients, respectively. Of 7 patients with MEN2A, 71% underwent prophylactic thyroidectomy. Only one 5-year-old patient (C634Y) had increased serum calcitonin level after prophylactic thyroidectomy in the MEN2A group. The only permanent complication, which did not occur in patients who underwent total thyroidectomy alone, was hypoparathyroidism (33% of patients). This permanent complication occurred with clinically developed MTC. No permanent postoperative complications occurred in patients aged 5-6 years. Conclusions Prophylactic thyroidectomy reduces recurrence and postoperative complications in pediatric patients with MEN2. Early thyroidectomy based on only calcitonin level could possibly reduce thyroidectomy delay.

Surgical Hypoparathyroidism

Surgical hypoparathyroidism is the most common cause of hypoparathyroidism and the result of intentional or inadvertent extirpation, trauma, or devascularization of the parathyroid glands. Surgical hypoparathyroidism may present as a medical emergency. Pediatric patients, those with Graves disease, and those undergoing extensive neck dissections or reoperative neck surgery are at particular risk for this complication. Extensive surgical expertise, immediate or delayed autotransplantation, and prophylactic and postoperative calcium/vitamin D supplementation in select patients are associated with a reduction in the risk of surgical hypoparathyroidism. Intraoperative parathyroid imaging is among novel strategies being investigated to mitigate surgical hypoparathyroidism in the intraoperative setting.

Disease impacts more than age on operative morbidity in children with Graves' disease after total thyroidectomy

BACKGROUND

In pediatric Graves' disease, operative morbidity after total thyroidectomy remains ill defined. The present study aimed to clarify whether total thyroidectomy entails greater operative morbidity in children with Graves' disease, in particular when they are very young, as compared with an age-matched reference group of children with hereditary C-cell disease who underwent total thyroidectomy at the same time.

METHODS

Operative morbidity after total thyroidectomy for Graves' disease was determined in relation to the child's age and in comparison with a reference group of age-matched children with hereditary C-cell disease.

RESULTS

Included in the study were 58 children with Graves' disease (51 girls and 7 boys) and 108 children with hereditary C-cell disease (59 girls and 49 boys). When children with Graves' disease and children with hereditary C-cell disease were compared across and within the 4 age increments (≤ 3, 4-6, 7-12, and 13-18 years), operative mortality did not differ significantly among and within age increments. Children with Graves' disease had a 1.7-fold greater overall risk of transient hypoparathyroidism (29% versus 17%; P = .073) than children with hereditary C-cell disease. Permanent hypoparathyroidism was nil in either group. Transient recurrent laryngeal nerve palsy, wound hemorrhage, and wound infections were infrequent (≤ 3% each), resolving spontaneously and after reoperation, respectively.

CONCLUSION

Disease impacts more than age on operative morbidity in children with Graves' disease after total thyroidectomy but is fairly low overall and rarely permanent in experienced hands.

Thyroid cancer in adolescents and young adults

In adolescents and young adults, thyroid cancer accounts for 13% of all invasive neoplasms, being three times more frequent in females, but overdiagnosis and overtreatment are common. There are two therapeutic approaches, one radical and no longer preferred in all instances, and the other conservative. Permanent complications of surgery and metabolic irradiation can affect quality of life and carry an economic burden. The overall survival rate approaches 100% for patients with differentiated thyroid cancer regardless of the extent of treatment. Medullary thyroid carcinoma is a very different entity, occurring most frequently in the context of hereditary tumor susceptibility syndromes.

Update on Multiple Endocrine Neoplasia Type 2: Focus on Medullary Thyroid Carcinoma

Multiple endocrine neoplasia type 2 (MEN2) is an autosomal dominant hereditary cancer syndrome caused by missense gain-of-function mutations in the RET proto-oncogene on chromosome 10. Specific RET mutations can predispose toward a particular phenotype and clinical course, with strong genotype–phenotype correlations. MEN2 is highly penetrant in medullary thyroid carcinoma (MTC), and it can be associated with bilateral pheochromocytoma and primary hyperparathyroidism. Two different clinical variants of MEN2 are known: MEN2A, which includes the familial subtype, and MEN2B. Treatment includes early thyroidectomy. Recommendations on the timing and extent of surgery are based on the RET mutation risk categories (moderate-, high-, or highest-risk) regarding the age of MTC onset. Early identification of patients with hereditary MTC has improved treatment outcomes. Previously, MTC was diagnosed based on clinical tumors; in contrast, with genetic screening, MTC can be diagnosed at preclinical disease states. This approach has resulted in a high cure rate and a much better prognosis for MTC. However, classification into one of the three RET mutation risk groups for predicting aggressiveness and prognosis has had limited impact. Increasing evidence has shown that patients with RET mutations in different risk classifications exhibit a broad spectrum of MTC aggressiveness during follow-up, with no relevant difference in survival. The specific germline activating mutation of the RET proto-oncogene appears to be the first determinant of the age of MTC onset, but, presumably, different regulatory events determine long-term tumor behavior.

Twenty-year experience of paediatric thyroid surgery using intraoperative nerve monitoring

BACKGROUND

There are few data on intermittent and continuous intraoperative nerve monitoring (IONM) during thyroidectomy in children.

METHODS

All children aged 18 years or younger who had standard thyroid operations using intermittent or continuous IONM between January 1998 and December 2016 were included in the study. The impact of age and type of IONM on basal amplitude, latency and complications after thyroidectomy were assessed.

RESULTS

A total of 504 children were included in the study. With continuous IONM, median basal amplitude and latency increased significantly with age, more on the left side (from 199 to 870 μV, and from 3·88 to 5·75 ms) than on the right (from 340 to 778 μV, and from 2·63 to 3·50 ms). Compared with intermittent IONM with needle electrode, continuous IONM with tube electrode resulted in an increase in median basal amplitude in children aged 13-18 years on both sides (from 675 to 778 μV on the right and from 450 to 870 μV on the left), and a decrease in median latency in all children older than 3 years: in children aged 4-6 years, from 4·20 to 3·00 ms on the right and from 6·10 to 4·63 ms on the left; in children aged 7-12 years, from 4·60 to 3·50 ms and from 6·00 to 5·25 ms respectively; and in children aged 13-18 years, from 4·60 to 3·50 ms and from 6·40 to 5·75 ms. Overall, wound infection, but not bleeding/haematoma or vocal fold palsy, affected younger children more: 3 per cent of children aged 3 years or less; 2 per cent of children aged 4-6 years; and 0 per cent of children aged over 6 years (P = 0·031). With continuous IONM, no wound infection, bleeding/haematoma or permanent vocal fold palsy was noted in any age group.

CONCLUSION

Continuous IONM measures nerve electrophysiology more accurately than intermittent IONM during thyroidectomy in children.

Advances in risk-oriented surgery for multiple endocrine neoplasia type 2

Genetic association studies hinge on definite clinical case definitions of the disease of interest. This is why more penetrant mutations were overrepresented in early multiple endocrine neoplasia type 2 (MEN2) studies, whereas less penetrant mutations went underrepresented. Enrichment of genetic association studies with advanced disease may produce a flawed understanding of disease evolution, precipitating far-reaching surgical strategies like bilateral total adrenalectomy and 4-gland parathyroidectomy in MEN2. The insight into the natural course of the disease gleaned over the past 25 years caused a paradigm shift in MEN2: from the removal of target organs at the expense of greater operative morbidity to close biochemical surveillance and targeted resection of adrenal tumors and hyperplastic parathyroid glands. The lead time provided by early identification of asymptomatic MEN2 carriers under biochemical surveillance delimits a 'window of opportunity', within which (i) pre-emptive total thyroidectomy alone is adequate, circumventing morbidity attendant to central node dissection; (ii) subtotal 'tissue-sparing' adrenalectomy is sufficient, trading the risk of steroid dependency for the risk of a second pheochromocytoma in the adrenal remnant and (iii) parathyroidectomy is limited to enlarged glands, trading the risk of postoperative hypoparathyroidism for the risk of leaving behind hyperactive parathyroid glands. Future research should delineate further the mutation-specific, age-dependent penetrance of pheochromocytoma and primary hyperparathyroidism to refine the risk-oriented approach to MEN2. The sweeping changes in the management of MEN2 since the new millenium hold the hope that death and major morbidity from this uncommon disease can be eliminated in our lifetime.

Long-term outcome of prophylactic thyroidectomy in children carrying RET germline mutations

Background

A comprehensive assessment has not been undertaken of long-term outcomes in children carrying germline RET mutations and undergoing prophylactic thyroidectomy with the aim of preventing medullary thyroid cancer (MTC).

Methods

A retrospective outcome study (1994–2017) of prophylactic thyroidectomy in children, with and without central node dissection, was performed at a tertiary surgical centre.

Results

Some 167 children underwent prophylactic thyroidectomy, 109 without and 58 with concomitant central node dissection. In the highest-risk mutational category, MTC was found in five of six children (83 per cent) aged 3 years or less. In the high-risk category, MTC was present in six of 20 children (30 per cent) aged 3 years or less, 16 of 36 (44 per cent) aged 4–6 years, and 11 of 16 (69 per cent) aged 7–12 years (P = 0·081). In the moderate-risk category, MTC was seen in one of nine children (11 per cent) aged 3 years or less, one of 26 (4 per cent) aged 4–6 years, three of 26 (12 per cent) aged 7–12 years, and seven of 16 (44 per cent) aged 13–18 years (P = 0·006). Postoperative hypoparathyroidism was more frequent in older children (32 per cent in the oldest age group versus 3 per cent in the youngest; P = 0·002), whether or not central node dissection was carried out. Three children developed recurrent laryngeal nerve palsy; all had undergone central node dissection (P = 0·040). All complications resolved within 6 months. Postoperative normalization of calcitonin serum levels was achieved in 114 (99·1 per cent) of 115 children with raised preoperative values. No residual structural disease or recurrence was observed.

Conclusion

Early prophylactic thyroidectomy is a viable surgical concept in experienced hands, sparing older children the postoperative morbidity associated with delayed neck surgery.

[Surgery of papillary thyroid microcarcinoma]

BACKGROUND

Different countries are currently reporting a substantial increase in the incidence rates of papillary thyroid microcarcinoma (PTMC).

OBJECTIVE

Presentation of diagnosis and surgical therapy of PTMC and discussion of a more conservative approach, such as active surveillance.

MATERIAL AND METHODS

Overview of the current guidelines from different countries and analysis of recent publications reporting the results of active surveillance of PTMC from Japan, Korea and the USA.

RESULTS

The majority of international guidelines for PTMC recommends thyroid lobectomy as the gold standard. Active surveillance as an alternative procedure is described in the Japanese guidelines (JSTS/JAES). Present surveillance studies including more than 1700 patients report a tumor growth in 8-14% of the cases during a median follow-up of up to 75 months. Tumor growth and lymph node metastases are detected most frequently in younger patients (below 40-50 years).

CONCLUSION

Active surveillance might serve as an alternative treatment option for older patients with PTMC. Since the median follow-up periods are currently not long enough, it seems difficult to draw definite conclusions of this procedure right now.

Does Surgical Volume Influence the Need for Second Surgery? A Pilot Study

Objective

To examine outcomes of pediatric thyroidectomy in the context of training background, institution, and experience of the surgeon.

Study Design

Case series with chart review.

Setting

A tertiary academic medical center and a pediatric hospital.

Subjects and Methods

Eighty-one thyroidectomy patients younger than 18 years. Outcomes were major complications (recurrent laryngeal nerve injury, permanent hypocalcemia, and wound infection), length of stay (LOS), and need for repeat surgery.

Results

Eighty-one patients, 39 from the University of Nebraska Medical Center and 42 from the Children’s Hospital and Medical Center–Omaha, were identified over a 12-year time period. No difference was found in surgeon training (otolaryngology/head and neck surgery vs general/pediatric surgery) for complications (1 vs 1, odds ratio [OR] = 0.76, 95% confidence interval [CI] = [0.05, 13.1]), LOS >1 day (5 vs 13, OR = 0.39, 95% CI = [0.13, 1.24]), or need for second surgery (4 vs 7, OR = 1.47, 95% CI = [0.39, 5.49]). Higher surgeon volume (≥12 surgeries) was found to be significant for decreased need for second surgery (3 vs 8, OR = 6.67, 95% CI = [1.57, 27.17]). Patients of higher-volume surgeons were 4.2 times more likely to stay in the hospital 1 day or less compared with those patients operated on by surgeons with less experience (7 vs 11, 95% CI = [1.59, 15.0]).

Conclusions

Need for second surgery in pediatric thyroidectomy may be predicted by surgical volume.

Perioperative determinants of transient hypocalcemia after pediatric total thyroidectomy

PURPOSE

We seek to identify risk factors associated with hypocalcemia after pediatric total thyroidectomy.

METHODS

We retrospectively reviewed patients younger than 21years undergoing total thyroidectomy between January 2002 and January 2016. We defined hypocalcemia as any serum calcium <8mg/dl or ionized calcium <1.0mmol/L. Perioperative risk factors were identified through multivariate logistic regression.

RESULTS

Ninety-one children underwent total thyroidectomy. The average age was 13.7±4.4years, and 77% were female. Transient hypocalcemia was diagnosed in 34% (n=31) of patients. There was one case of permanent hypoparathyroidism. Predictors of transient hypocalcemia included age (OR 0.87, 95% CI 0.8-0.97, p=0.01), lymphadenectomy (OR 6.6, 95% CI 1.7-31.6, p=0.01), and hyperthyroidism (OR 13.3, 95% CI 1.3-1849, p=0.03). Patients with malignancy undergoing central (OR 7.1, 95% CI 1.5-33.4, p=0.01) or central plus lateral lymphadenectomy (OR 6.33, 95% CI 1.0-40.1, p=0.05) had significantly increased risk for transient hypocalcemia. Malignancy, MEN2A/B, goiter, preoperative calcium supplementation, incidental parathyroid removal, and postoperative PTH <15pg/ml were not associated with transient hypocalcemia.

CONCLUSIONS

Younger age, hyperthyroidism, and concomitant lymphadenectomy during total thyroidectomy increase risk of developing transient hypocalcemia. Malignant cases with central or central plus lateral lymphadenectomy are also at increased risk. Aggressive perioperative management of hypocalcemia should be initiated in patients with these risk factors.

LEVEL OF EVIDENCE

2b.