The role of MR imaging in detecting nodal disease in thyroidectomy patients with rising thyroglobulin levels

T1 relaxation: Chemo-physical fundamentals of magnetic resonance imaging and clinical applications

A knowledge of the complex phenomena that regulate T1 signal on Magnetic Resonance Imaging is essential in clinical practice for a more effective characterization of pathological processes. The authors review the physical basis of T1 Relaxation Time and the fundamental aspects of physics and chemistry that can influence this parameter. The main substances (water, fat, macromolecules, methemoglobin, melanin, Gadolinium, calcium) that influence T1 and the different MRI acquisition techniques that can be applied to enhance their presence in diagnostic images are then evaluated. An extensive case illustration of the different phenomena and techniques in the areas of CNS, abdomino-pelvic, and osteoarticular pathology is also proposed. CRITICAL RELEVANCE STATEMENT: T1 relaxation time is strongly influenced by numerous factors related to tissue characteristics and the presence in the context of the lesions of some specific substances. An examination of these phenomena with extensive MRI exemplification is reported. KEY POINTS: The purpose of the paper is to illustrate the chemical-physical basis of T1 Relaxation Time. MRI methods in accordance with the various clinical indications are listed. Several examples of clinical application in abdominopelvic and CNS pathology are reported.

Incidence of Persistence and Recurrence of Differentiated Thyroid Cancer in Post-surgical Cases From a Tertiary Care Hospital in Dubai, United Arab Emirates

Background Despite the excellent prognosis of differentiated thyroid carcinoma, recurrence remains a major concern. However, the persistence of thyroid cancer post-thyroidectomy is not uncommon. We aimed to characterise patients who underwent re-operative surgery for differentiated thyroid carcinoma and analyse the percentage of re-operations that truly were for "recurrent" disease versus the management of persistent disease. Methods We conducted a retrospective review of the hospital database, analysing patients who visited the nuclear medicine department at Mediclinic City Hospital, a tertiary care hospital in Dubai, United Arab Emirates, between 2015 and 2022. The study included patients with differentiated thyroid carcinoma who underwent re-operations after total thyroidectomy. Recurrence was defined as the development of disease after a patient had undetectable thyroglobulin and negative radiological scans within one year of the first surgery. Cases were categorised as "recurrent", "persistent", or "unable to classify" in the event of missing data. Results Out of 836 patients diagnosed with differentiated thyroid carcinoma who visited the nuclear medicine department, 71 underwent re-operations. The mean age of these patients was 44.4 years (CI 41.7-47.0), of whom 78.9% were females. Almost half (46.5%) underwent re-operations within the first year, and 98.6% were diagnosed with papillary thyroid carcinoma. We were able to classify 63.4% of cases (n=45) as persistent disease, while 24 cases were categorised as "unable to classify". Only two cases met the criteria for recurrent disease. Conclusion The majority of cases previously classified as "recurrent" in differentiated thyroid carcinoma were found to be a persistent disease, possibly indicating inadequate therapy. Further research may be required to explore the reasons behind this eye-opening rate of disease persistence. This highlights an area for improvement in the management and future outcomes of differentiated thyroid carcinoma patients.

Parapharyngeal Metastasis of Papillary Carcinoma of Thyroid Gland: A Case Report and a Review of the Literature

Papillary carcinoma is the most frequently encountered differentiated thyroid carcinoma. Usually, metastasis occurs along lymphatic pathways in the central compartment and along the jugular chain. Nevertheless, lymph node metastasis in the parapharyngeal space (PS) is a rare but possible event. In fact, a lymphatic pathway has been identified that connects the upper pole of the thyroid and the PS. We describe the case of a 45-year-old man with a two-month history of a right neck mass. He underwent a complete diagnostic path that highlighted the presence of a parapharyngeal mass associated with the presence of a thyroid nodule suspected to be malignant. The patient underwent surgery (thyroidectomy and removal of the PS mass that was found to be a metastatic node of papillary thyroid carcinoma). The aim of this case is to underline the importance of detecting these kinds of lesions. Nodal metastasis in PS from thyroid cancer is a rare occurrence that is not easily detectable by a clinical examination until the metastasis reaches a considerable dimension. Computed tomography (CT) and magnetic resonance imaging (MRI) permit early identification, but unfortunately, these are not usually employed as a first-level imaging technique in patients with thyroid cancer. The treatment of choice is surgery with a transcervical approach that allows for better control of the disease and of the anatomical structures. Non-surgical treatments are usually reserved for patients with advanced disease, with satisfactory results.

Nomogram incorporating preoperative clinical and ultrasound indicators to predict aggressiveness of solitary papillary thyroid carcinoma

Objective

To construct a nomogram based on preoperative clinical and ultrasound indicators to predict aggressiveness of solitary papillary thyroid carcinoma (PTC).

Methods

Preoperative clinical and ultrasound data from 709 patients diagnosed with solitary PTC between January 2017 and December 2020 were analyzed retrospectively. Univariate and multivariate logistic regression analyses were performed to identify the factors associated with PTC aggressiveness, and these factors were used to construct a predictive nomogram. The nomogram's performance was evaluated in the primary and validation cohorts.

Results

The 709 patients were separated into a primary cohort (n = 424) and a validation cohort (n = 285). Univariate analysis in the primary cohort showed 13 variables to be associated with aggressive PTC. In multivariate logistic regression analysis, the independent predictors of aggressive behavior were age (OR, 2.08; 95% CI, 1.30-3.35), tumor size (OR, 4.0; 95% CI, 2.17-7.37), capsule abutment (OR, 2.53; 95% CI, 1.50-4.26), and suspected cervical lymph nodes metastasis (OR, 2.50; 95% CI, 1.20-5.21). The nomogram incorporating these four predictors showed good discrimination and calibration in both the primary cohort (area under the curve, 0.77; 95% CI, 0.72-0.81; Hosmer-Lemeshow test, P = 0.967 and the validation cohort (area under the curve, 0.72; 95% CI, 0.66-0.78; Hosmer-Lemeshow test, P = 0.251).

Conclusion

The proposed nomogram shows good ability to predict PTC aggressiveness and could be useful during treatment decision making.

Advances in knowledge

Our nomogram-based on four indicators-provides comprehensive assessment of aggressive behavior of PTC and could be a useful tool in the clinic.

Imaging of Treated Thyroid and Parathyroid Disease

The thyroid and parathyroid glands are endocrine structures located in the visceral space of the infrahyoid neck. Imaging plays a critical role in the evaluation of patients with thyroid cancer, both in the pre and posttreatment setting. Disorders of thyroid function, that is, hyperthyroidism and hypothyroidism, are also fairly common, although imaging utilization is less frequent with these conditions. Parathyroid dysfunction results in disordered calcium metabolism. Imaging is frequently applied in the preoperative assessment of these patients undergoing parathyroidectomy; however, routine imaging in the postoperative setting is uncommon. Parathyroid carcinoma is rare; however, imaging may be used in the pre and posttreatment setting.

Common blind spots and interpretive errors of neck imaging

Complex anatomy and a wide spectrum of diseases in the head and neck predispose interpretation of neck imaging to cognitive pitfalls and perceptual errors. Extra attention to common blind spots in the neck and familiarity with common interpretive challenges could aid radiologists in preventing these diagnostic errors.

Surgical management of parapharyngeal lymph node metastases from thyroid carcinoma with transcervical approach

BACKGROUND

Parapharyngeal lymph node metastasis is very rare in patients with thyroid carcinoma. In this study, we elucidated on the clinical features, diagnosis, surgical treatment, and outcomes for patients with parapharyngeal lymph node metastases from thyroid carcinoma.

METHODS

Patients with thyroid carcinoma who had been subjected to surgery through the transcervical approach at our institution between April 1999 and January 2019 were retrospectively enrolled in this study.

RESULTS

Parapharyngeal lymph node metastases were successfully resected through the transcervical approach in all the 97 patients. There were 32 treatment-naïve patients, while 65 patients had a history of treatment before parapharyngeal lymph node metastases. All 97 cases of parapharyngeal lymph node metastases were detected by enhanced CT scans. Lateral neck lymph nodes metastases were confirmed in 96 patients. Unexpected postoperative neurological side effects were reported in 11 (11%) patients, including dysphagia in 5 (5%) patients, Horner's syndrome in 2 (2%) patients, glossal deviation in 3 (3%) patients, and asymmetrical mouth in 1 (1%) patient. During the follow-up period, 6 of the 97 patients exhibited parapharyngeal lymph node recurrence (recurrence rate 6.2%). The incidence of distant metastases was 44.3% (43 out of 97). The 5- and 10-year disease-specific survival was 93.4% and 88.9%, respectively.

CONCLUSION

Parapharyngeal lymph node metastases should be considered in patients with widespread cervical lymph node metastases. Enhanced CT scan is one of the best methods for diagnosing such metastases. Surgical resection through the transcervical approach is an effective and safe option for patients with parapharyngeal lymph node metastases from thyroid carcinoma. Moreover, parapharyngeal lymph node metastasis is associated with distant metastases that may lead to poor prognosis.

Metastatic thyroid carcinoma to the parapharyngeal and retropharyngeal spaces: Systematic review with seven newly reported cases describing an uncommon presentation of a common disease

BACKGROUND

Metastatic thyroid carcinoma to retropharyngeal and parapharyngeal (RP/PP) lymph nodes is rare. Literature suggests previous lateral neck dissection (LND) may alter patterns of lymphatic drainage in the neck, predisposing to these less common sites of spread.

METHODS

PRISMA-guided systematic search for all published cases detailing RP/PP metastases of well-differentiated thyroid carcinoma from 1970 to 2019.

RESULTS

Seventy articles were identified and 44 were included, along with seven cases treated at our institution, totaling 239 cases. Cases represented both retropharyngeal (60.7%) and parapharyngeal (39.3%) metastases identified in the initial (27.6%) and recurrent (72.4%) setting.

CONCLUSION

RP/PP metastases generally present in the recurrent setting. RP/PP metastases often represent high-risk disease, and surgical treatment is recommended.

Diagnostic performance of MRI to detect metastatic cervical lymph nodes in patients with thyroid cancer: a systematic review and meta-analysis

AIM

To evaluate the diagnostic performance of magnetic resonance imaging (MRI) in the diagnosis of metastatic cervical lymph nodes.

MATERIALS AND METHODS

Ovid-MEDLINE and EMBASE databases were searched up until 12 June 2018. Eleven articles were included in the qualitative systematic review and nine of the 11 in the quantitative analysis. Two radiologists independently performed data extraction and methodological quality assessment using the Quality Assessment of Diagnostic Accuracy Studies-2 tool. A qualitative systematic review and quantitative analysis were performed, followed by a meta-regression analysis to determine factors causing heterogeneity.

RESULTS

The pooled sensitivity and specificity in the diagnosis of metastatic cervical lymph nodes were 80% (95% confidence interval [CI]: 68-88%) and 85% (95% CI: 63-95%), respectively. The sensitivity and false-positive rate (correlation coefficient, 0.655) showed a positive correlation due to a threshold effect, which was responsible for heterogeneity across the studies, as indicated by a Q-test (p<0.01) and Higgins I² statistic (sensitivity, I²=90.11%; specificity, I²=92.49%). In the meta-regression analysis, fat-suppressed imaging, and the analysis method were significant factors influencing the heterogeneity in diagnostic performance.

CONCLUSIONS

MRI shows moderate diagnostic performance in the diagnosis of metastatic lymph nodes in patients with thyroid cancer in the neck. MRI may be an optional or complementary imaging method to ultrasound or computed tomography (CT) in thyroid cancer patients.

Diagnostic Capabilities of MRI Versus 18F FDG PET-CT in Postoperative Patients with Thyroglobulin Positive, 131I-negative Local Recurrent or Metastatic Thyroid Cancer

BACKGROUND

The detection of recurrence or metastasis might be challenging in patients, who underwent total thyroidectomy and radioactive iodine therapy for Differentiated Thyroid Carcinoma (DTC), with increased serum Thyroglobulin (Tg) levels and negative 131I whole body scan (131I-WBS) results.

AIMS

The purpose of this study was to compare the ability of Magnetic Resonance Imaging (MRI) and 18F-fluorodeoxyglucose Positron Emission Tomography/Computed Tomography (18F FDG PET-CT) to detect recurrence or cervical and upper mediastinal metastases in postoperative DTC patients who had negative 131I-WBS despite elevated serum Tg levels.

STUDY DESIGN

This study has a retrospective study design.

METHODS

We evaluated cervical and upper mediastinal MRI and 18F FDG PET-CT of 32 postoperative patients with DTC (26 patients with papillary thyroid carcinoma and 6 patients with follicular thyroid carcinoma).

RESULTS

We evaluated 44 lesions in 32 patients. For all lesions, the Positive Predictive Value, (PPV) Negative Predictive Value (NPV), sensitivity, specificity, and accuracy of MRI were 81.4%, 76.4%, 84.6%, 72.2%, and 79.5% respectively. The PPV, NPV, sensitivity, specificity, and accuracy of 18F FDG PET-CT were 100.0%, 85.7%, 88.4%, 100.0%, and 93.1%, respectively.

CONCLUSION

Although we could not replace 18F FDG PET-CT, MRI might be used as an adjunct to 18F FDG PET-CT for the evaluation of recurrent or cervical and upper mediastinal metastatic thyroid cancers; however, MRI is inadequate for the detection of metastases in small lymph nodes.

Minimally Invasive Video-Assisted Surgical Management for Parapharyngeal Metastases From Papillary Thyroid Carcinoma: A Case Series Report

Background: Papillary thyroid carcinoma (PTC) is the most prevalent cancer type in the endocrine system. Metastases to parapharyngeal lymph nodes (PPLNs) are rare. Herein, we reported a case series of PTC patients with PPLN metastases operated on by using the minimally invasive video-assisted (MIVA) technique to evaluate the safety and effectiveness of this technique. Method: In this single-institutional study, six consecutive PTC patients with PPLN metastases between January 2012 and July 2018 were enrolled. All PPLNs were managed by the MIVA technique. Result: Six patients (three women and three men) who underwent surgery were enrolled in the current study. The median age of patients was 40.5 years (39-66). Five patients (83.3%) were diagnosed with primary PTC with PPLN metastases, and one patient had PTC recurrence in the PPLNs 17 years after her first PTC surgery. Surgical treatment was successful in all patients, and the median operative time and bleeding volume were 185 (100-280) min and 85 (30-120) ml, respectively. None of the patients experienced post-operative complications except for one patient who experienced dysphagia, which resolved within 3 months. During a median follow-up of 15 months (10-31), none of the patients exhibited recurrence or persistent disease. Conclusion: The MIVA transcervical approach was technically feasible and reliable, with less invasiveness for PTC patients with PPLN metastases. Future studies are needed to accumulate more experience, investigate the indications of the technique, and determine the long-term oncological safety.

2016 Russian clinical practice guidelines for differentiated thyroid cancer diagnosis and treatment

В представленных клинических рекомендациях обсуждаются современные подходы к диагностике и лечению дифференцированного рака щитовидной железы у взрослых. Изменения в настоящей редакции Клинических рекомендаций касаются показаний к пункционной биопсии, скринингового определения концентрации кальцитонина, унификации заключений цитологического исследования, новых подходах к послеоперационной динамической стратификации риска рецидива, показаний к супрессивной и заместительной терапии, таргетной терапии йоднегативных форм дифференцированного рака щитовидной железы.

Parapharyngeal Metastasis of Papillary Thyroid Carcinoma

BACKGROUND

Nodal involvement of papillary thyroid carcinoma (PTC) commonly occurs in the paratracheal region and the internal jugular chain. Lymph node metastasis in the parapharyngeal space (PPS) is rare. In this report, we describe our experience and surgical outcomes of patients with PPS metastasis of PTC.

METHODS

Clinical data of patients with PTC who underwent surgery at our institution between January 2006 and December 2013 were retrospectively reviewed, and 22 patients with PPS metastasis were enrolled.

RESULTS

There were 2 primary and 20 secondary cases of PPS metastasis. Involvement of the jugular nodes was noted before or at the time of PPS metastasis detection in all cases. A transcervical surgical approach with partial resection of the mandibular angle was performed in 21 patients, while 1 patient underwent extirpation of the PPS metastasis via a transoral approach. Although curative resection was performed in 21 patients, the PPS metastasis was not removable in 1 patient owing to an invaded internal carotid artery at the skull base. Twelve and 6 patients had locoregional and distant recurrence, respectively. Of the 12 patients with locoregional recurrence, isolated locoregional recurrence in the PPS occurred in 1. Eight patients died of distant or locoregional recurrence, with a median survival time of 91.7 months.

CONCLUSIONS

For patients who experience recurrence after thyroid surgery, the possibility of PPS metastasis should be considered. In this series, all patients with PPS metastasis also had previous unilateral or bilateral cervical metastasis. Despite curative attempt, most patients experienced local or distant recurrence.

2015 American Thyroid Association Management Guidelines for Adult Patients with Thyroid Nodules and Differentiated Thyroid Cancer: The American Thyroid Association Guidelines Task Force on Thyroid Nodules and Differentiated Thyroid Cancer

BACKGROUND

Thyroid nodules are a common clinical problem, and differentiated thyroid cancer is becoming increasingly prevalent. Since the American Thyroid Association's (ATA's) guidelines for the management of these disorders were revised in 2009, significant scientific advances have occurred in the field. The aim of these guidelines is to inform clinicians, patients, researchers, and health policy makers on published evidence relating to the diagnosis and management of thyroid nodules and differentiated thyroid cancer.

METHODS

The specific clinical questions addressed in these guidelines were based on prior versions of the guidelines, stakeholder input, and input of task force members. Task force panel members were educated on knowledge synthesis methods, including electronic database searching, review and selection of relevant citations, and critical appraisal of selected studies. Published English language articles on adults were eligible for inclusion. The American College of Physicians Guideline Grading System was used for critical appraisal of evidence and grading strength of recommendations for therapeutic interventions. We developed a similarly formatted system to appraise the quality of such studies and resultant recommendations. The guideline panel had complete editorial independence from the ATA. Competing interests of guideline task force members were regularly updated, managed, and communicated to the ATA and task force members.

RESULTS

The revised guidelines for the management of thyroid nodules include recommendations regarding initial evaluation, clinical and ultrasound criteria for fine-needle aspiration biopsy, interpretation of fine-needle aspiration biopsy results, use of molecular markers, and management of benign thyroid nodules. Recommendations regarding the initial management of thyroid cancer include those relating to screening for thyroid cancer, staging and risk assessment, surgical management, radioiodine remnant ablation and therapy, and thyrotropin suppression therapy using levothyroxine. Recommendations related to long-term management of differentiated thyroid cancer include those related to surveillance for recurrent disease using imaging and serum thyroglobulin, thyroid hormone therapy, management of recurrent and metastatic disease, consideration for clinical trials and targeted therapy, as well as directions for future research.

CONCLUSIONS

We have developed evidence-based recommendations to inform clinical decision-making in the management of thyroid nodules and differentiated thyroid cancer. They represent, in our opinion, contemporary optimal care for patients with these disorders.

Retrospective imaging study on the diagnosis of pathological false positive iodine-131 scans in patients with thyroid cancer

Iodine-131 (I-131) therapy and post-therapy I-131 scanning are essential in the management of differentiated thyroid cancer (DTC). However, pathological false positive I-131 scans can lead to misdiagnosis and inappropriate I-131 treatment. This retrospective study aimed to investigate the best imaging modality for the diagnosis of pathological false positive I-131 scans in a DTC patient cohort, and to determine its incidence. DTC patient data archived from January 2008 to January 2010 was retrieved. Post-therapeutic I-131 scans were conducted and interpreted. The imaging modalities of magnetic resonance imaging (MRI), computed tomography and ultrasonography were applied and compared to check all suspected lesions. Biopsy or needle aspiration was conducted for patients who consented to the acquisition of histopathological confirmation. Data for 156 DTC patients were retrieved. Only 6 cases of pathological false-positives were found among these (incidence, 3.85%), which included 3 cases of thymic hyperplasia in the mediastinum, 1 case of pleomorphic adenoma in the parapharyngeal space and 1 case of thyroglossal duct cyst in the neck. MRI was demonstrated as the best imaging modality for diagnosis due to its superior soft tissue resolution. However, no imaging modality was able to identify the abdominal false positive-lesions observed in 2 cases, one of whom also had thymic hyperplasia. In conclusion, pathological false positive I-131 scans occurred with an incidence of 3.85%. MRI was the best imaging modality for diagnosing these pathological false-positives.

Use of transoral sonography with an endocavitary transducer in diagnosis, fine-needle aspiration biopsy, and intraoperative localization of retropharyngeal masses

OBJECTIVE

The purpose of this article is to describe the use of transoral sonography in the diagnosis, fine-needle aspiration (FNA) biopsy, and intraoperative localization of retropharyngeal masses.

MATERIALS AND METHODS

We reviewed images and data for eight patients with a retropharyngeal mass identified on CT, MRI, or PET/CT as being suspicious for a metastatic Rouviere node. Transoral ultrasound was performed using a commercially available endorectal or endovaginal transducer. Transoral ultrasound-guided FNA biopsy was performed using a needle guide attached to the transducer shaft. Color and power Doppler imaging were used to identify the internal carotid artery and jugular vein and to plan the safest path to the targeted mass. The mass was intraoperatively localized by marking the mucosa with a permanent marker or by injecting methylene blue.

RESULTS

There were six patients with a history of thyroid cancer (five papillary cancers and one medullary cancer), one patient with a history of esthesioneuroblastoma, and one patient with no history of cancer. Transoral ultrasound imaging was successful in all eight patients. Transoral ultrasound-guided FNA biopsy was performed in four patients, and a satisfactory cytologic diagnosis was obtained in all cases, although in one of those four cases, an additional core biopsy with an 18-gauge needle was performed to completely rule out lymphoma. Six patients underwent a transoral resection of the lesion. In three of them, the lesion was localized intraoperatively by making a mark on the mucosa and in one case by adding transoral ultrasound-guided injection of methylene blue.

CONCLUSION

Transoral ultrasound can be used to visualize, sample, and localize abnormal masses in the retropharyngeal space, such as metastatic Rouviere nodes in patients with a history of head and neck cancer.

Thyroid cancer in children and adolescents

PURPOSE OF REVIEW

Paediatric thyroid cancer is a rare disease, but its incidence is rising in recent reports. This review aims at integrating recent findings into the current optimal diagnostic and therapeutic approach.

RECENT FINDINGS

The causal relationship of differentiated thyroid cancer (DTC) to radiation exposure is increasingly unravelled. Research progressively uncovers the genetic basis, such as RET (rearranged during transfection)/papillary thyroid cancer (PTC) rearrangement and RET-mutations. Knowledge of oncogenic signalling pathways nowadays starts to help finetuning diagnosis, prognosis and treatment. This knowledge complements the current state-of-the-art of paediatric thyroid cancer treatment. In childhood, DTC presents at a more advanced stage and implies higher recurrence rates, recurrences often occurring decades later. Treatment should minimize not only these recurrences but also long-term treatment sequelae. Total thyroidectomy and central compartment dissection by a high-volume surgeon and radioactive iodine is the preferred approach for most children with DTC. For children with medullary thyroid cancer within the MEN2 framework, when possible, prophylactic thyroidectomy is performed. Unfortunately, frequently, the diagnosis is still made at a later stage, and then requires total thyroidectomy with dissection of the central compartment and the lateral neck, when involved.

SUMMARY

The management complexity, the essential long-term follow-up and the lifetime burden of eventual complications demands management of paediatric thyroid cancer by physicians with the highest expertise. In such hands, excellent results can be obtained.

Imaging of thyroid carcinoma with CT and MRI: approaches to common scenarios

Computed tomography (CT) and magnetic resonance imaging (MRI) can play an important role in preoperative and post-treatment assessment of thyroid malignancy. The radiologist should be aware of the pathological behavior of thyroid carcinoma, and the characteristic imaging appearance of the primary tumor and metastases. This review describes the approach to imaging thyroid cancer on CT and MRI for four common scenarios: detection of the incidental thyroid nodule, evaluation of thyroid metastases, presurgical imaging for invasive disease, and evaluation for recurrence in the post-treatment neck.

Magnetic resonance imaging of the pediatric neck: an overview

Evaluation of neck lesions in the pediatric population can be a diagnostic challenge, for which magnetic resonance (MR) imaging is extremely valuable. This article provides an overview of the value and utility of MR imaging in the evaluation of pediatric neck lesions, addressing what the referring clinician requires from the radiologist. Concise descriptions and illustrations of MR imaging findings of commonly encountered pathologic entities in the pediatric neck, including abnormalities of the branchial apparatus, thyroglossal duct anomalies, and neoplastic processes, are given. An approach to establishing a differential diagnosis is provided, and critical points of information are summarized.

American Thyroid Association consensus review and statement regarding the anatomy, terminology, and rationale for lateral neck dissection in differentiated thyroid cancer

BACKGROUND

Cervical lymph node metastases from differentiated thyroid cancer (DTC) are common. Thirty to eighty percent of patients with papillary thyroid cancer harbor lymph node metastases, with the central neck being the most common compartment involved. The goals of this study were to: (1) identify appropriate methods for determining metastatic DTC in the lateral neck and (2) address the extent of lymph node dissection for the lateral neck necessary to control nodal disease balanced against known risks of surgery.

METHODS

A literature review followed by formulation of a consensus statement was performed.

RESULTS

Four proposals regarding management of the lateral neck are made for consideration by organizations developing management guidelines for patients with thyroid nodules and DTC including the next iteration of management guidelines developed by the American Thyroid Association (ATA). Metastases to lateral neck nodes must be considered in the evaluation of the newly diagnosed thyroid cancer patient and for surveillance of the previously treated DTC patient.

CONCLUSIONS

Lateral neck lymph nodes are a significant consideration in the surgical management of patients with DTC. When current guidelines formulated by the ATA and by other international medical societies are followed, initial evaluation of the DTC patient with ultrasound (or other modalities when indicated) will help to identify lateral neck lymph nodes of concern. These findings should be addressed using fine-needle aspiration biopsy. A comprehensive neck dissection of at least nodal levels IIa, III, IV, and Vb should be performed when indicated to optimize disease control.

The first report of bilateral retropharyngeal lymph node metastasis from papillary thyroid carcinoma and review of the literature

The sites of lymph node metastasis of papillary thyroid carcinomas are typically the paratracheal and jugular lymph nodes. On the other hand, metastasis to the retropharyngeal or parapharyngeal nodes from papillary thyroid carcinomas is very rare. During the last two decades, limited to cases with a histologically definite diagnosis by surgery, only 39 cases have been reported. All reported cases were unilateral retropharyngeal or parapharyngeal node metastasis except one metachronous bilateral case, and there were no reports of simultaneous bilateral cases within our literature review. We report three cases of retropharyngeal node metastasis from thyroid papillary carcinoma, including a case of bilateral nodal metastasis. Retropharyngeal node metastasis was successfully resected in all three patients by the transcervical approach. As pointed out in past reports, this report also suggests that prior neck dissection and/or metastasis to cervical lymph nodes might alter the direction of lymphatic drainage to the retrograde fashion, resulting in the unusual metastasis to the retropharyngeal lymph nodes, and there is a possibility of a bilateral pattern. Also, it is necessary to consider the possibility of metastasis from a papillary thyroid carcinoma in the differential diagnosis of lymph node swelling in the parapharyngeal space.

Translational imaging of lymphatics in cancer

Imaging in the lymphatic system has gone through much advancement over the past 70 years since its beginnings. In this review, we will examine the modalities available for lymphatic imaging. We will explore the modern uses of early modalities, such as ultrasound as well as more modern modalities, such as Positron-Emission Tomography (PET). We will also describe some of the new modalities currently in development and their potential uses for the future as well as some of the current imaging modalities being studied in animal models.

Technical refinement of ultrasound-guided transoral resection of parapharyngeal/retropharyngeal thyroid carcinoma metastases

BACKGROUND

The transoral approach to the parapharyngeal and retropharyngeal space (PPS/RPS) for the management of well-differentiated thyroid carcinoma (WDTC) has been previously described in other articles. However, limited exposure with this approach can be a challenge.

METHODS

This is a retrospective review of 6 patients who underwent ultrasound-guided transoral excision of PPS/RPS WDTC metastases from October 2003 to March 2009 in a cancer center setting. Ultrasound-guided methylene blue dye injection of the node was used in 3 patients to facilitate intraoperative identification. The technique, safety, and feasibility of the procedure are described in this study.

RESULTS

Successful resection of the metastases was accomplished in all cases without intraoperative complication. The 1 definite recurrence was further treated with transmandibular excision.

CONCLUSION

Transoral excision of PPS/RPS WDTC metastases with ultrasound-guided methylene blue dye injection into the metastatic node is safe, feasible, and may further improve intraoperative identification of metastases in poorly accessible locations in the head and neck.

Transoral Surgical Approach for Retropharyngeal Node Involvement in I-131-Negative 18-fluoro-2-deoxyglucose Positron Emission Tomography-Positive Recurrent Thyroid Cancer

Transoral pharyngotomy is a viable minimally invasive approach for resection of metastatic thyroid cancer in retropharyngeal lymph nodes in highly select patients. A few authors have already reported on its safe application with excellent outcomes. We herein describe a case where the technique is assisted with the Omniguide CO(2) laser system to safely access and remove a metastatic node in the retropharyngeal space of a 24 year-old Caucasian woman. Furthermore, her disease was I-131-negative and positron emission tomography-positive, demonstrating the technique is still feasible in this dedifferentiated cancer state.