Carotid body paragangliomas: a systematic study on management with surgery and radiotherapy

Tumor volume changes after stereotactic, hypofractionated and conventional radiotherapy in paragangliomas of head and neck

BACKGROUND

The aim of this study is comparison the effectiveness of stereotactic, hypofractionated and conventional radiotherapy assessed by the tumor volume changes of paraganglioma located in the head and neck region concerning fractional and total doses.

METHODS

We analyzed 76 patients after radiotherapy due to paraganglioma who were assigned to 3 groups considering fractional (≤2 Gy, 3-5.5 Gy, ≥6 Gy) and total (≤20 Gy, 21-40 Gy, >40 Gy) doses. The volumes of irradiated tumors were measured and compared based on diagnostic images performed before and after the treatment.

RESULTS

The mean tumor volume after the treatment with the lowest fractional dose (≤2 Gy) was decreased by 14.4 cm3. In patients treated with higher fractional doses (>2 Gy), the mean tumor volumes decreased by less than 1 cm3 for hypofractionated and stereotactic radiotherapy. 15.9 cm3 reduction of the mean tumor volume after the treatment with the highest RT total dose (>40 Gy) was stated. In patients treated with total doses ≤20 Gy and 21-40 Gy, the mean tumor volume was stable and reduced by 1.15 cm3, respectively. The analysis demonstrates a statistically significant (p < 0.05) treatment advantage in patients after the lowest fractional and highest total doses.

CONCLUSION

The reduction of the tumor's volume was reported after conventional and unconventional radiotherapy. The most significant depletion of the paraganglioma volume was noted after a factional dose ≤2 Gy and a total dose >40 Gy.

Approach to the Patient: Concept and Application of Targeted Radiotherapy in the Paraganglioma Patient

Paragangliomas can metastasize, posing potential challenges both in symptomatic management and disease control. Systemic targeted radiotherapies using 131I-MIBG and 177Lu-DOTATATE are a mainstay in the treatment of metastatic paragangliomas. This clinical scenario and discussion aim to enhance physicians' knowledge of the stepwise approach to treat these patients with paraganglioma-targeted radiotherapies. It comprehensively discusses current approaches to selecting paraganglioma patients for targeted radiotherapies and how to choose between the two radiotherapies based on specific patient and tumor characteristics, when either therapy is feasible, or one is superior to another. The safety, efficacy, toxicity profiles, and optimization of these radiotherapies are also discussed, along with other therapeutic options including radiotherapies, available for patients besides these two therapies. Perspectives in radiotherapies of paraganglioma patients are outlined since they hold promising approaches in the near future that can improve patient outcomes.

Current management of carotid body tumors

Carotid body tumors (CBTs) are neoplasms that occur at the bifurcation of the carotid artery and are pathologically classified as paragangliomas. In the 4th edition of the WHO classification, paragangliomas are categorized as neoplasms with malignant potential. Clinically, about 5% of CBTs present with malignant features such as metastasis. Currently, it is challenging to distinguish between tumors with benign courses and those that present malignantly. Recent advances in genetic testing have elucidated the genetic characteristics of paragangliomas, including carotid body tumors. Over 20 genes have been identified as being involved in tumor development. Particularly in head and neck paragangliomas, abnormalities in genes related to succinate dehydrogenase are frequently observed. Research is ongoing to understand the mechanisms by which these genes contribute to tumor development. The definitive treatment for CBTs is surgical resection. These tumors are prone to bleeding and often adhere firmly to the carotid artery, making intraoperative bleeding control challenging. The risk of lower cranial nerve paralysis is relatively high, and there is a risk of stroke because of manipulation of the carotid artery. Preoperative evaluation with angiography is essential, and a multi-disciplinary surgical team approach is necessary. In cases where the tumor is difficult to resect or has metastasized, radiation therapy or chemotherapy are employed. Clinical trials involving targeted molecular therapies and radiopharmaceuticals have recently been conducted, with some applied clinically. The development of various new treatments is anticipated, providing hope for therapeutic options in refractory cases.

Microsurgery in carotid body paraganglioma

Objectives

In carotid paraganglioma surgery, magnification is crucial to properly evaluate the anatomical relationships between mass, carotid wall, cranial nerves, tumour vascular supply and fascial envelope. The aims of this study are to describe the microsurgical technique, along with the underlying microsurgical anatomy, and to assess outcomes in terms of disease control, complications and functional results.

Methods

Twenty-six patients, accounting for 29 carotid paragangliomas, treated with microsurgery by the same senior surgeon over a 35-year period, were included.

Results

No carotid injury requiring repair, nor peri- or post-operative stroke occurred in this series. No surgical injury of the main trunk of VII to XII cranial nerves occurred. Complete excision was obtained in all cases and no recurrence was observed during follow-up.

Conclusions

The small study size and its retrospective nature suggests caution; however, our results show that microsurgery can allow a safe and precise dissection of the carotids and nerves.

Malignant carotid body tumors: What we know, what we do, and what we need to achieve. A systematic review of the literature

Malignant carotid body tumors (MCBT) are rare and diagnosed after detection of nodal or distant metastases. This systematic review (SR) focuses on MCBT initially approached by surgery. Preferred Reporting Items for SR and Meta-Analysis (MA) guided the articles search from 2000 to 2023 on PubMed, Scopus, and Web of Science. Among 3548 papers, 132 (337 patients) were considered for SR; of these, 20 (158 patients) for MA. Malignancy rate was 7.3%, succinate dehydrogenase (SDH) mutation 17%, age at diagnosis between 4th and 6th decades, with a higher prevalence of females. MCBTs were mostly Shamblin III, with nodal and distant metastasis in 79.7% and 44.7%, respectively. Malignancy should be suspected if CBT >4 cm, Shamblin III, painful or otherwise symptomatic, at the extremes of age, bilateral, with multifocal disease, and SDHx mutations. Levels II-III clearance should be performed to exclude nodal metastases and adjuvant treatments considered on a case-by-case basis.

Management of phaeochromocytoma and paraganglioma in patients with germline SDHB pathogenic variants: an international expert Consensus statement

Adult and paediatric patients with pathogenic variants in the gene encoding succinate dehydrogenase (SDH) subunit B (SDHB) often have locally aggressive, recurrent or metastatic phaeochromocytomas and paragangliomas (PPGLs). Furthermore, SDHB PPGLs have the highest rates of disease-specific morbidity and mortality compared with other hereditary PPGLs. PPGLs with SDHB pathogenic variants are often less differentiated and do not produce substantial amounts of catecholamines (in some patients, they produce only dopamine) compared with other hereditary subtypes, which enables these tumours to grow subclinically for a long time. In addition, SDHB pathogenic variants support tumour growth through high levels of the oncometabolite succinate and other mechanisms related to cancer initiation and progression. As a result, pseudohypoxia and upregulation of genes related to the hypoxia signalling pathway occur, promoting the growth, migration, invasiveness and metastasis of cancer cells. These factors, along with a high rate of metastasis, support early surgical intervention and total resection of PPGLs, regardless of the tumour size. The treatment of metastases is challenging and relies on either local or systemic therapies, or sometimes both. This Consensus statement should help guide clinicians in the diagnosis and management of patients with SDHB PPGLs.

The Additional Value of Somatostatin Receptor Positron Emission Computed Tomography ([68Ga]Ga-DOTATOC PET/CT) Compared with Magnetic Resonance Imaging of the Head and Neck Region in Paraganglioma Patients: A Pilot Study

The Dutch guideline for patients suspected of head and neck paragangliomas (HNPGLs) recommends magnetic resonance imaging (MRI) and/or computed tomography (CT) of the head and neck area. Additionally, it suggests considering additional nuclear imaging. The aim of this study was to evaluate the outcomes of [68Ga]Ga-DOTATOC PET/CT compared to MRI in patients with suspected HNPGLs and carriers of genetic variations.

METHODS

In this single-center pilot study, retrospective data were obtained from consecutive patients between 2016 and 2023. Both MRI and [68Ga]Ga-DOTATOC PET/CT were performed within 12 months. The primary outcome was the location of HNPGLs.

RESULTS

A total of 25 consecutive patients were included, and 7 patients (28.0%, p = 0.5) showed differences between the imaging modalities, of whom 5 patients had unexpected localizations with additional uptake by somatostatin receptors (SSTR) on the [68Ga]Ga-DOTATOC PET/CT.

CONCLUSIONS

The authors recommend performing baseline imaging with [68Ga]Ga-DOTATOC PET/CT (if available) in variant carriers and using MRI/CT for follow-up according to the regional protocol, thereby shifting the gold standard for baseline imaging from MRI/CT to [68Ga]Ga-DOTATOC PET/CT.

A Global Bibliometric Analysis of the Top 100 Most Cited Articles on Carotid Body Tumors

The carotid body, situated at the common carotid artery bifurcation, comprises specialized glomus cells responsible for sensing blood oxygen, carbon dioxide, pH, and temperature changes, crucial for regulating breathing and maintaining oxygen homeostasis. Carotid body tumors (CBTs), arising from these cells, are rare, representing only 0.5% of head and neck tumors, often presenting as benign, slow-growing, vascularized masses. In February 2023, this bibliometric analysis was conducted, which involved screening 1733 articles from the Web of Science database. The screening process was based on citation count, and articles were selected for inclusion based on specific criteria that focused on CBTs located within the carotid bifurcation. Rigorous selection involved independent screening and data extraction by four authors. The top 100 articles, published between 1948 and 2019, totaled 6623 citations and were authored by 98 unique first authors from 22 countries and 77 institutions, spanning 42 journals. Treatment articles were the predominant category, comprising 49% of the literature. This analysis offers insights into publication trends, identifies literature gaps, and outlines areas of research focus, providing a valuable resource to guide future studies on CBTs.

Role of Preoperative Embolization in Surgical Management of Carotid Body Tumors: A Systematic Review and Meta-Analysis

The objective of this study is to evaluate the effect of preoperative embolization on carotid body tumor resection. A systematic review and meta-analysis were conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. PubMed, Scopus, and Web of Science were screened for studies published between 2010 and 2022. Primary outcomes investigated were intraoperative blood loss, operative time, length of hospital stay, and perioperative complications such as transient ischemic attack (TIA)/stroke, vascular injury, and cranial nerve injury (CNI). A random effects model was used in cases where study heterogeneity was high. Overall, 25 studies were included in the systematic review, involving 1649 patients: 23 studies were eligible for meta-analysis. The incidence of vascular injury was significantly less in the preoperative embolization group (odds ratio (OR) = 0.60; 95% CI: 0.42-0.84; P = .003). There was no statistically significant difference between the two groups regarding intraoperative blood loss, operative time, length of hospital stay, incidence of TIA/stroke, and CNI. Subgroup analyses did not demonstrate significant difference between Shamblin I, II, and III subgroups regarding operative time. This meta-analysis found preoperative embolization to be significantly beneficial in reducing incidence of vascular injury.

Clinical consensus guideline on the management of phaeochromocytoma and paraganglioma in patients harbouring germline SDHD pathogenic variants

Patients with germline SDHD pathogenic variants (encoding succinate dehydrogenase subunit D; ie, paraganglioma 1 syndrome) are predominantly affected by head and neck paragangliomas, which, in almost 20% of patients, might coexist with paragangliomas arising from other locations (eg, adrenal medulla, para-aortic, cardiac or thoracic, and pelvic). Given the higher risk of tumour multifocality and bilaterality for phaeochromocytomas and paragangliomas (PPGLs) because of SDHD pathogenic variants than for their sporadic and other genotypic counterparts, the management of patients with SDHD PPGLs is clinically complex in terms of imaging, treatment, and management options. Furthermore, locally aggressive disease can be discovered at a young age or late in the disease course, which presents challenges in balancing surgical intervention with various medical and radiotherapeutic approaches. The axiom-first, do no harm-should always be considered and an initial period of observation (ie, watchful waiting) is often appropriate to characterise tumour behaviour in patients with these pathogenic variants. These patients should be referred to specialised high-volume medical centres. This consensus guideline aims to help physicians with the clinical decision-making process when caring for patients with SDHD PPGLs.

Vagal paragangliomas

PURPOSE OF REVIEW

A vagal paraganglioma is a rare head and neck tumor arising from the paraganglionic tissue within the perineurium of the vagus nerve, anywhere along the course of the nerve. Due to its proximity to the internal carotid artery, the internal jugular vein and the lower cranial nerves, this disorder poses significant diagnostic and therapeutic challenges. The diagnostic workup and management keep on evolving.

RECENT FINDINGS

This article gives a concise update of the clinical spectrum and the current state-of-the-art diagnostic workup and management of vagal paraganglioma.

SUMMARY

Every patient with suspected vagal paraganglioma needs to be evaluated by a multidisciplinary team. The management strategy is selected depending on the growth rate of the tumor, the age and fitness of the patient, the number of affected cranial nerves, the metabolic activity of the paraganglioma, and the eventual multicentricity. An algorithm guiding the clinician through the different treatment options is presented.

Unilateral synchronous masses of the neck revealing a malignant Carotid Body Tumor: A case report and literature review

INTRODUCTION AND IMPORTANCE

Paraganglioma (PG); also known as Glomus Tumor, is a rare neoplastic entity that originates from neural crest cells. It can manifest in different patterns, chiefly benign but others are locally invasive and malignant in behavior. Due to the prevalence of other more common types of neck masses and Paraganglioma's exceeding rarity, misdiagnoses can easily take place, and this results in higher patient morbidity and mortality rates. Preoperative diagnosis constitutes a major clinical challenge, especially in patients with a previous surgical history in the neck region like our patient.

CASE PRESENTATION

We are hereby presenting the case of a 56-year-old female with a known history of total thyroidectomy, who presented to our department with a progressively growing painful recurring neck mass two years following her total thyroidectomy. The preoperative diagnostic assessment revealed two unilateral synchronous masses encapsulating the Right Common Carotid Artery and occupying the common carotid bifurcation.

CLINICAL DISCUSSION

Complete surgical resection of the lesions after isolation from the surrounding anatomical structures was done. Subsequent histopathological and immunohistochemical analyses of the specimens established the diagnosis of a Carotid Body Tumor (CBT).

CONCLUSION

CBTs are rare vascular neoplasia, and they possess the potential for malignant transformation. This neoplasia warrants investigation and documentation to establish innovative diagnostic parameters and accomplish timely surgical interventions. To the best of our knowledge, this is the first documented case of a unilateral synchronous malignant Carotid Body Tumor from Syria. Surgery remains the treatment of choice, while radio-/chemotherapy is reserved for non-surgical cases only.

Risk Factors for Stroke After Carotid Paraganglioma Surgery

BACKGROUND

The Carotid Paraganglioma Cooperative International Registry (CAPACITY) is an international registry composed of 1,432 patients with carotid body tumors (CBT) from 11 centers from 4 countries. The aim of this study was to identify risk factors for patients who presented stroke after carotid paraganglioma resection.

METHODS

Clinical characteristics and demographics of patients who presented transoperatively and postoperatively stroke from the CAPACITY database were retrospectively gathered. Regression analysis was performed using single logistic regression with Omnibus' test for possible factors that might contribute to present stroke.

RESULTS

Out of 1,432 patients, 8 (0.5%) female patients presented stroke. Median age was 53 years (range: 41-70 years). Six strokes occurred transoperatively, diagnosed clinically in the immediate postoperative period. Of them, none of the patients received any further treatment. Three of them died on postoperative day 2, 3, and 4. Two patients developed stroke during the first 24 postoperative hours, patients showed dysarthria, and aphasia. One of them was reintervened with thrombectomy due to thrombosis of the common carotid artery the other patient was treated conservatively. Median follow-up was 16 months (range: 2-72 months). Single logistic regression analysis revealed a history of diabetes mellitus (odds ratio (OR) 7.62), carotid artery disease (OR 17.51), and vascular lesion (OR 2.37) to have significantly increased odds of stroke during CBT surgery.

CONCLUSIONS

In the present study history of diabetes mellitus, carotid artery disease, and vascular lesion had increased odds of stroke during CBT surgery. Findings are limited by low event rate and even larger cohorts are needed to fully define preventive preoperative strategies for preventing stroke.

Solitary Plasmacytoma of the Jugular Foramen: A Case Report and Review of the Differential Diagnosis

Jugular foramen tumours are uncommon, deeply located, and eloquently situated, making their diagnosis and management challenging. Paragangliomas and other benign tumours comprise the large majority of lesions in this region, but malignant tumours are occasionally identified. We report a unique case of a solitary plasmacytoma of the jugular foramen resembling a jugulotympanic paraganglioma. A solitary plasmacytoma of the jugular foramen is both rare in location and in disease presentation, as most plasma cell neoplasms are diagnosed as multiple myeloma. Our 75-year-old patient presented with symptoms typical for a jugular foramen tumour. Although there are radiographic features which help differentiate paragangliomas from other benign and malignant tumours, plasmacytomas are highly vascular and can demonstrate a local infiltrative spread which can mimic the radiographic appearance of a paraganglioma. Clinicians should consider plasma cell neoplasms in the differential when faced with an unusual presentation of a jugular foramen lesion. Our patient was treated with definitive radiotherapy to 45 Gy, which was very effective local treatment for the solitary plasmacytoma.

Carotid body paraganglioma metastatic to spine causing cord compression: a case report

BACKGROUND

Carotid body tumors (CBTs) are rare neuroendocrine neoplasms arising near the carotid bifurcation with a reported incidence of 1 to 2 cases in 100,000 patients. Most CBTs are sporadic, benign, slow-growing, and non-secreting, but untreated CBTs can grow locally to compress the nearby blood vessels, esophagus, and airway. Regional metastases can occur in 5% to 10% of cases, but distant metastases are exceedingly rare, occurring in roughly 1-2% of cases. As such, the optimal treatment for metastatic CBTs is not well-defined. We report a rare case of a patient with CBT distant metastases causing spinal cord compression.

CASE PRESENTATION

A 40-year-old African American female presented with a right neck mass, headaches, vertigo, tinnitus, hoarseness, and dysphagia. Imaging demonstrated a Shamblin II right neck mass; subsequent transcervical resection and pathology showed a carotid body paraganglioma. The patient recurred locally near the carotid bifurcation, so she underwent Stereotactic Body Radiation Therapy to the recurrent right neck disease. She later re-presented with new onset bilateral lower extremity weakness, dysmetria, and numbness. She was found to have metastatic disease to the thoracic spine causing spinal cord compression. She underwent laminectomy, tumor resection, and posterior fixation followed by adjuvant radiation therapy. She was started on systemic therapy with sunitinib. She eventually progressed with metastatic disease to the right iliac bone, which was treated with palliative radiotherapy. Second line systemic therapy with capecitabine and temozolomide was started. At last follow up, the patient was asymptomatic with stable persistent disease.

CONCLUSIONS

Paragangliomas often exhibit a prolonged interval to the development of progression; locoregional recurrences or rare distant metastases have been reported to occur as many as 20 years from diagnosis. The natural course of CBTs in other cases as well as the present case call into question the idea that CBTs are truly benign; instead CBTs may be indolent tumors with metastatic potential. Treatment choices for CBTs include surgical resection, radiation therapy, and systemic therapy, though the optimal treatment regimen for metastatic CBTs is not well-defined. A more advanced understanding of CBT pathophysiology, disease classification, risk stratification, and treatment options is needed to improve outcomes for patients.

Resection of Carotid Body Tumors in Patients of Advanced Age: Experience From a Single Center

INTRODUCTION

Resection of carotid body tumor (CBT) in patients of advanced ages has not been appreciated.

OBJECTIVES

This study aims to assess the clinical characteristics and perioperative comorbidities for CBT resection in patients of advanced age and to validate the application of an "isolated island" technique for extirpation of CBT.

METHODS

Eight patients of advanced age (≥60 years) who underwent CBT resection were enrolled as the study group (SG). Another 29 patients of younger age (<45 years old) underwent CBT extirpation were assigned as the control group (CG). The perioperative issues were compared between these 2 groups.

RESULTS

The "isolated island" technique was successfully applied for resection of CBT in all 37 patients. The prevalence of Shamblin classification I, II, and III tumors in the SG was 12.5%, 62.5%, and 25%; whereas in the CG was 10.3%, 55.2%, and 34.5%, respectively. Bilateral CBT was observed in 7 patients of the CG and none in the SG. Vascular reconstruction was required for 1 (12.5%) patient in the SG, while it was required for 8 (27.6%) patients in the CG. Postoperative vocal cord palsy occurred in 37.5% of patients in SG, whereas the vocal cord palsy (34.5%) and dysphagia (6.9%) were commonly encountered in CG. In addition to postoperative length of stay (P = .004), no significant difference for operative time, intraoperative blood loss, or mortality were observed between these 2 groups (P > .05).

CONCLUSION

Extirpation of CBT in patients of advanced age is rationale in appropriately selected patients. The "isolated island" technique is safe for CBT resection with seemingly low complication rates.

[Surgical treatment of cervical neurovascular bundle tumors]

OBJECTIVE

To determine the main principles of a patient-oriented individual approach to diagnosis and surgical treatment of cervical neurovascular bundle tumors considering the capabilities of neurosurgical hospital.

MATERIAL AND METHODS

There were 92 patients with cervical soft tissue tumors affecting neurovascular bundle. Age of patients ranged from 9 to 81 years (mean 47). There were 65.1% women and 34.9% men. We found chemodectoma (47.4%), neurofibroma (15.8%), neurinoma (13.2%), papillary thyroid cancer (5.3%), salivary gland heterotopia (5.3%), salivary gland adenocarcinoma (5.3%), Hodgkin lymphoma (2.6%), hemangioendothelioma (2.6%) and cavernous lymphangioma (2.6%). Diagnostic algorithm included neurological examinations, Doppler ultrasound of supra-aortic arteries, transcranial ultrasound of cerebral vessels, MRI of cervical soft tissues, CT-AG, MR-AG, CT-perfusion, direct selective angiography.

RESULTS

A total of 94 surgical interventions were performed. All surgeries were performed using surgical optics and neurophysiological monitoring of cranial nerves IX, X, XII. We chose resection technique depending on localization, histological features and blood supply of tumor. En-bloc resection was performed in 46 cases, removal of fragments - in 23 cases, intracapsular resection of tumor followed by resection of the capsule - in 26 cases. Total and subtotal resection was performed in 68 (72%) and 23 (24%) cases, respectively. Three (4%) patients underwent partial resection of infiltrative tumors for carotid artery decompression and histological analysis. In 76% of cases, baseline symptoms of disease regressed after surgery. Persistent moderate bulbar disorders were observed in 16 patients (17%). Ischemic complications with additional surgical interventions were observed in 2 cases.

CONCLUSION

Patients with cervical soft tissue tumors require individual approach regarding choosing the optimal surgical treatment including possible preoperative embolization of tumor, en-bloc or intracapsular resection and carotid artery repair.

Efficacy and safety of 225Ac-DOTATATE targeted alpha therapy in metastatic paragangliomas: a pilot study

PURPOSE

In this study, we aim to evaluate the efficacy and safety of 225AC-DOTATATE targeted alpha therapy in advanced-stage paragangliomas (PGLs).

METHODS

Nine (6 males and 3 females) consecutive patients with histologically proven PGLs were treated with 225Ac-DOTATATE targeted alpha therapy (TAT) and concomitant radiosensitizer, capecitabine, at 8-weekly intervals up to a cumulative activity of ~ 74 MBq. The primary endpoint included evaluating therapy response and disease control rate (DCR) using the RECIST 1.1 criteria. Additional secondary endpoints comprised clinical response assessment using EORTC QLQ-H&N35 questionnaire, Karnofsky Performance Scale (KPS), Eastern Cooperative Oncology Group performance status (ECOG), analgesic score (AS), dose alterations of anti-hypertensive drugs (anti-HTN), and the safety and side-effect profile evaluation as per CTCAE criteria version 5.0.

RESULTS

Following 225Ac-DOTATATE treatment, morphological response revealed partial response in 50%, stable disease in 37.5%, and disease progression in 12.5%, with a DCR of 87.5%. Similarly, the symptomatic response was remarkable, and anti-HTN drugs were stopped in 25% and reduced in 37.5%. Another significant finding in our study revealed a morphologic DCR of 66.6% (2/3) in patients who failed previous lutetium-177 peptide receptor radionuclide therapy (177Lu-PRRT). Regarding the KPS, ECOG, and AS performance scores, a notable improvement was observed post-225Ac-DOTATATE treatment. The QLQ-H&N35 symptom scores evaluated in seven H&N PGL patients showed significant improvement in all aspects. No improvement in sexual function was noted (P = 0.3559). Despite the significant reduction in the analgesic score post-treatment (P = 0.0031), the QLQ-H&N35 revealed only marginal significance concerning the intake of pain killers (P = 0.1723). No grade III/IV hematological, renal, and hepatological toxicities were noted.

CONCLUSION

The evidence from this study suggests 225Ac-DOTATATE therapy is effective and safe in the treatment of advanced-stage PGLs and also reports a clear benefit even in patient's refractory to the previous 177Lu-PRRT.

Treatment decision and estimation of growth of head and neck paragangliomas

PURPOSE

Head and neck paragangliomas are slow growing tumors where observation has become more widely accepted. Tumor growth rate as well as predictors of increased tumor growth were analyzed with the goal to identify factors to better predict disease progression and counsel patients.

MATERIALS AND METHODS

Multi-institutional retrospective cohort study from 2011 to 2020.

RESULTS

130 head and neck paragangliomas in 125 patients were analyzed. 38 were observed (30.4%), 16 radiated (12.8%), and 71 underwent surgery (56.8%). Surgical patients were significantly younger (p = 0.038) and with more genetically mediated paragangliomas (p = 0.026). Significantly more patients were asymptomatic in the observation group (p = 0.005). Of the 39 observed tumors, 43.6% (n = 17) grew with a tumor doubling time of 5.67 years. More than half of the observed paragangliomas had no growth. When examining symptoms postoperatively and at follow-up, the surgical cohort had significantly more worsening symptoms (p = 0.007) and new cranial neuropathies (p = 0.031).

CONCLUSIONS

Head and neck paragangliomas have slow growth rates if they grow at all. Patients in the surgical cohort had more clinical symptoms at presentation and worsening postoperative symptoms.

Paragangliomas of the head and neck

Paragangliomas are rare neuroendocrine tumors that can be found from the skull base to the pelvis. Head and neck paragangliomas have been historically treated with surgery. However, surgical resection adds risk of injury to vascular structures and cranial nerves that can lead to morbidity such as hoarseness, dysarthria, dysphagia, or aspiration. Recently, improved understanding of the behavior of these tumors and increasing experience in non-surgical treatments such as observation and radiation therapy, have changed the paradigms of management of this entity. Multiple series now show a trend towards a more conservative management, with a higher percentage of patients being observed or treated with radiotherapy. Several factors should be taken into consideration when deciding the most appropriate treatment for head and neck paragangliomas, starting by differentiating carotid body tumors from non- carotid body tumors. In general, surgical resection is normally recommended for carotid body tumors as the complications from treatment are usually minimal. In contrast, for non- carotid body tumors, surgery is often associated with significant functional impairment due to cranial nerve paralysis. As such, non-surgical treatment is now usually recommended for this subset of head and neck paragangliomas. In young patients with no comorbidities and a small to medium carotid body tumors, surgery should be considered. Moreover, surgery should be offered for secreting tumors, malignant tumors, tumors with rapid growth or increase in symptomatology, and when radiotherapy cannot be performed. Conversely, conservative management with active surveillance or radiotherapy can be offered in the remaining cases in order to avoid unnecessary morbidity while still providing acceptable tumor control.

Contemporary management of paragangliomas of the head and neck

Head and neck paragangliomas (HNPGLs) are rare neuroendocrine tumors typically arising from nonsecretory head and neck parasympathetic ganglia. Historically thought of as aggressive tumors that warranted equally aggressive surgical intervention, evidence has emerged demonstrating that the vast majority of HNPGLs are slow growing and indolent. It is also now recognized that a large proportion of HNPGLs are hereditary with succinate dehydrogenase gene mutations typically implicated. These recent advances have led to significant changes in the way in which clinicians investigate and treat HNPGLs with most now opting for more conservative treatment strategies. However, a proportion of patients present with more aggressive disease and still require nonconservative treatment strategies. Recent studies have sought to determine in which groups of patients the morbidity associated with treatment is justified. We summarize the recent advances in the understanding and management of these tumors and we provide our recommendations regarding the management of HNPGLs.

Head and Neck Paragangliomas in the Czech Republic: Management at the Otorhinolaryngology Department

Head and neck paragangliomas (HNPGLs) are rare neuroendocrine tumors, comprising only 3% of all head and neck tumors. Early diagnosis forms an integral part of the management of these tumors. The two main aims of any treatment approach are long-term tumor control and minimal cranial nerve morbidity. The scope of this article is to present our case series of HNPGLs to stress most important clinical aspects of their presentation as well as critical issues of their complex management. Thirty patients with suspected HNPGLs were referred to our otorhinolaryngology clinic for surgical consultation between 2016–2020. We assessed the demographical pattern, clinicoradiological correlation, as well as type and outcome of treatment. A total of 42 non-secretory tumors were diagnosed—16.7% were incidental findings and 97% patients had benign tumors. Six patients had multiple tumors. Jugular paragangliomas were the most commonly treated tumors. Tumor control was achieved in nearly 96% of operated patients with minimal cranial nerve morbidity. Surgery is curative in most cases and should be considered as frontline treatment modality in experienced hands for younger patients, hereditary and secretory tumors. Cranial nerve dysfunction associated with tumor encasement is a negative prognostic factor for both surgery and radiotherapy. Multifocal tumors and metastasis are difficult to treat, even with early detection using genetic analysis. Detecting malignancy in HNPGLs is challenging due to the lack of histomorphological criteria; therefore, limited lymph node dissection should be considered, even in the absence of clinical and radiological signs of metastasis in carotid body, vagal, and jugular paragangliomas.

Development and validation of an improved classification and risk stratification system for carotid body tumors: Multinational collaborative cohort study

BACKGROUND

This study aims to develop and validate a new classification system that better predicts combined risk of neurological and neurovascular complications following CBT surgery, crucial for treatment decision-making.

METHODS

Multinational retrospective cohort study with 199 consecutive cases. A cohort of 132 CBT cases was used to develop the new classification. To undertake external validation, assessment was made between the actual complication rate and predicted risk by the model on an independent cohort (n = 67).

RESULTS

Univariate analyses showed statistically significant associations between developing a complication and the following factors: craniocaudal dimension, volume, Shamblin classification, and Mehanna types. In the multivariate prognostic model, only Mehanna type remained as a significant risk predictor. The risk of developing complications increases with increasing Mehanna type.

CONCLUSIONS

We have developed and then validated a new classification and risk stratification system for CBTs, which demonstrated better prognostic power for the risk of developing neurovascular complications after surgery.

Cervical paragangliomas: experience of 114 cases in 14 years

Introduction and objective

To report a single center experience with carotid body paraganglioma cases that were treated by the same surgeon in a city with high prevalence of paragangliomas due to high altitude.

Methods

We retrospectively investigated the demographic, clinicopathological and radiological data of 104 patients diagnosed with cervical paragangliomas between 2003 and 2017. The patients were classified according to the Shamblin classification.

Results

In this study a total of 104 patients (33 male and 71 female, with a mean age of 54.6 ± 13 years) diagnosed with cervical paragangliomas located on carotid bifurcation between 2003 and 2017 were included. Among those patients, 10 presented with bilateral tumors and in total, 114 paragangliomas were managed in this period. The mean diameter of the tumors was 5.12 ± 1.45 cm. Malignant tumor was determined in only one (0.9%) patient. All patients were operated. In 12 patients with the tumor diameter larger than 5 cm, preoperative coil embolization was achieved. In 14 patients, preoperative angiographic embolization was employed and in 4 patients intraoperative sclerosing agent injections were performed. Facial paralysis was observed in 2 patients and dysphagia was present in 1 patient, Horner syndrome was seen in 1 patient and hoarseness was reported in 7 patients after operation. All those complications improved during follow-up. Mortality was not reported in any cases.

Conclusion

Surgery is the definitive treatment for patients with cervical paragangliomas. Although, it may be difficult in patients with the advanced Shamblin types, in experienced hands, complication rates are very low.

Surgical outcomes and factors associated with malignancy in carotid body tumors

OBJECTIVE

To compare the surgical outcomes of benign and malignant carotid body tumor (CBT), and to evaluate the associated factors of malignant CBT.

METHODS

Patients who underwent surgical resection of CBT from 2005 to 2018 in a tertiary center were reviewed retrospectively. The common study follow-up end date was December 31, 2019. The tumor size was measured as the maximum transverse diameter on computed tomography scan. Surgical outcomes of benign and malignant CBT were compared. Associated factors of malignancy were analyzed by multivariate logistic analysis.

RESULTS

There were 229 patients undergoing CBT resection. Sixteen patients were diagnosed with malignant CBT. The median follow-up time was 66 months (range, 6-142 months). Basic information including age, sex, course of disease, family history, lesion side, tumor size, and Shamblin classification showed no significant differences between the benign and malignant CBT groups. Patients with malignant CBTs showed a higher rate of preoperative symptoms (31.3% vs 12.2%; P < .05). The rates of vascular reconstruction or repair (P < .01) and neurologic complications (P < .05) were significantly higher in the malignant CBT group. In addition, a significantly longer average procedural time was required for malignant CBTs (P < .05). However, the estimated blood loss and length of hospital stay showed no significant difference. Multivariate logistic regression analysis revealed that the malignant odds of CBT with bilateral lesions (P = .0042; odds ratio, 8.30; 95% confidence interval, 1.84-35.88) or CBT with preoperative symptoms (P = .0016; odds ratio, 7.59; 95% confidence interval, 2.13-27.89) were high.

CONCLUSIONS

Compared with benign CBT, malignant CBT is prone to invasive clinical behaviors, resulting in an increased possibility of vascular reconstruction or repair during the surgery as well as postoperative neurologic complications. In addition, the malignant odds of CBT with bilateral lesions or CBT with preoperative symptoms are high.

Is Preoperative Embolization Necessary for Carotid Paraganglioma Resection: Experience of a Tertiary Center

PURPOSE

This study was designed to investigate whether preoperative embolization is a useful procedure to decrease blood loss and neurovascular complications for carotid body tumor (CBT) surgery or not.

METHODS

Medical records of our tertiary care center from 2012 to 2019 were scanned for patients who underwent surgery for CBT, retrospectively. Age, gender, complaint and head and neck examination findings at the time of presentation, preoperative complete blood count parameters, imaging records (cervical magnetic resonance imaging and carotid artery angiography), Shamblin classification, tumor size, intraoperative findings, and postoperative complications were noted.

RESULTS

A total of 26 patients were operated due to CBT between 2012 and 2019 in our clinic; preoperative arterial embolization was performed to 15 (57.7%) patients, and 11 (42.3%) patients were operated without embolization. Youngest patient was 24 years old, while oldest was 69 years and mean age was 44.35 ± 12.73. (embolization group: ages ranging between 24 and 64 with a mean of 41.5 ± 11.02 years; in nonembolization group: ages ranging between 26 and 69 with a mean of 48.1 ± 14.3). Embolization status was not significantly related to cranial nerve injury, vascular injury, overall complications, and hematocrit decrease. Arterial injury is more likely to occur with increasing Shamblin class (r = .39; P = .04). Tumor size is not found to be significantly related to cranial nerve injury, vascular injury, overall complications, and hematocrit decrease, but cranial nerve injury and vascular injury were more likely to occur in large tumors (r = .34; P = .089 and r = .34; P = .087, respectively). Age was significantly and negatively correlated to vascular injury (r = -.51; P = .05). Vascular injury was significantly correlated with gender (male predominance: r = -.64; P = .000).

CONCLUSION

Although preoperative arterial embolization is considered to attenuate the complication risk, we found that there was no significant difference among the patients with or without embolization.

Simple and complex carotid paragangliomas. Three decades of experience and literature review

BACKGROUND

Carotid paragangliomas are rare tumors. They are usually unique, non-secreting, resectable, and benign. However, additional rare cases of complex tumors (bilateral, secretory, nonresectable, or malignant) complicate the management and final outcomes.

METHODS

Records of paragangliomas from our hospital are reviewed. Criteria defining complex paragangliomas have been previously defined. These are compared with those of the simple group.

RESULTS

Fifty patients, two groups: simple (n = 39) and complex (n = 11). The patients in the complex group were significantly younger (47.7 vs 63.8 years). Postoperative nerve complications (45.4% vs 6.3%) and mortality during follow-up (27.3% vs 0%) were significantly more common in the complex group. Vascular complications (0% vs 3.1%) and early mortality (0%) were similarly in both groups.

CONCLUSIONS

Patients with complex carotid paragangliomas are heterogeneous. The former are younger, exhibit a high degree of diagnostic and therapeutic complexity, and have poorer morbidity and mortality. Surgical experience and interdisciplinary collaboration are essential.

Head and neck paragangliomas: 30-year experience

BACKGROUND

We aimed to review our experience and the changing trends in the management of head and neck paragangliomas (HNPG) over the last three decades.

METHODS

We retrospectively reviewed 103 patients with HNPG treated at our center (1986-2017). We included patients treated with surgery, radiotherapy, and patients maintained under active surveillance.

RESULTS

Of the surgically treated patients (n = 79), 20% (12/59) of the carotid body tumors (CBT) had a cranial nerve deficit as sequela compared to 95% (19/20) of the non-CBT. Radiotherapy controlled growth in all tumors treated with this modality (n = 10). Of the initially observed patients, 70% (14/20) remained stable and did not require additional treatment. Stratifying by decades, there was a progressive increase in patients initially attempted to be observed and a decrease in upfront surgery. No deaths attributable to the HNPG were encountered.

CONCLUSIONS

Surgery is an effective treatment for CBT. Nonsurgical treatment should be considered for non-CBT.

Locally invasive giant spinal paraganglioma

Cauda equina paragangliomas are neuroendocrine tumours rarely encountered in neurosurgical practice. Large cauda equina paragangliomas with an intradural and extradural component, dense adhesion to nerve roots and high vascularity are surgically challenging and mandate meticulous operative dissection. The presence of extensive bony erosion can lead to spinal instability requiring solid instrumentation and fixation. We recommend resection of large cauda equina paragangliomas in a staged fashion with the aim of gross total resection and spinal stabilisation.

[Paraganglioma of the cauda equina region: Report of 9 cases]

INTRODUCTION

The paraganglioma of the cauda equina is a rare tumor, the diagnosis is morphological and the immunohistochemistry provides a definite diagnosis. The objective of our study is to specify the clinical signs, radiological and associated pathological criteria and to compare our data with those of the literature.

PATIENTS AND METHOD

This is a retrospective study of nine cases of paragangliomas of the cauda equina diagnosed in our department from 2003 to 2018. The median age of the patients was 50 years-old with a male predominance (sex ratio: 3,5/1). All patients had preoperative magnetic resonance imaging (MRI) and surgery to remove the tumor. The diagnosis was performed after HES (Hematoxylin Eosin Saffron) and immunohistochemical sections examination.

RESULTS

Radiculalgia was the chief symptom of these tumors. MRI showed an oval lesion uniformly enhanced by Gadolinium in the eight patients whose records were available. Histologically, the tumors had a lobular and trabecular pattern with neuroendocrine-like cells and a rich vascularization. By immunohistochemistry, the cells expressed chromogranin, synaptophysin and CD56.

DISCUSSION AND CONCLUSION

Paragangliomas of the cauda equina are rare, benign tumors. Except for cases of secreting tumors, the preoperative diagnosis is difficult. MRI is useful and may reveal radiological features suggestive of these tumors. However, it is rare for the diagnosis to be made before surgery. The diagnosis is established by histological examination and immunohistochemical techniques must be used to confirm the diagnosis. The paragangliomas of the cauda equina are well encapsulated tumors whose complete excision is curative. When the excision is incomplete, treatment with radiotherapy is recommended. Long-term clinical and radiological monitoring is recommended because of the slow evolution of the tumor and the potential for recurrence.

The clinical characteristics and outcomes of carotid body tumors in Chinese patients: A STROBE-compliant observational study

This study aims to investigate the clinical characteristics and outcomes of carotid body tumors in Chinese patients in the last decade. A systematic search was conducted without limits and included studies published between January 2006 and December 2016 according to PubMed, the Chinese Science Citation Database, the China Science Periodical Database and the China National Knowledge Infrastructure. Relevant synonyms for the search terms "paraganglioma" and "carotid body tumor" were applied, and the clinical data were evaluated and analyzed. There were 1810 cases of CBTs reported in the last decade, of which females accounted for 60.22%, and the mean age was 40.60 years, with most cases being sporadic (98.51%). Surgical resection was performed in 1791 cases: vessel repair occurred in 38.88% of the cases, carotid ligation occurred in 1.42% of the cases, and 1.05% of the patients refused treatment. Some patients underwent selective embolization, and the results showed that embolization could decrease procedure time and blood loss (P < .01). Stroke and death occurred in 1.95% and 0.39% of patients, respectively. Malignant CBTs accounted for 4.30% of cases, and the metastatic sites involved were local metastasis (46.88%), lung (31.25%), bone (21.88%), liver (12.50%), and brain (9.38%). The overall survival rate was 98.87% 36 months after the procedure, and the survival rate of metastatic cases was 56.25% 6 months after recurrence; however, only 21.88% of metastatic cases received radiotherapy. The CBTs of Chinese patients showed some clinical features that were different from those of Western patients.

[Surgical treatment options for cervical paragangliomas]

The therapies available for the rare tumor entity of cervical paraganglioma (PG) are currently undergoing a paradigm shift. The treatment of choice for small carotid body tumors, malignant and active endocrine tumors is surgical resection; however, for locally advanced carotid body tumors and vagal PG, surgical therapy should be critically evaluated. Due to the immediate proximity of these hypervascularized tumors to the caudal cranial nerves, there is a risk of severe nerve damage with a significant impairment of quality of life after resection, particularly for locally advanced cervical PG, emphasizing further the importance of a restrictive surgical strategy. External radiotherapy can provide an equivalent primary therapeutic option with respect to the rate of recurrence and is accompanied by a lower morbidity. The slow rate of tumor progression and the multifocality of the familial variant of cervical PG or significant comorbidities in older, asymptomatic patients warrant a less aggressive treatment strategy for these tumors. When a wait and scan approach is implemented, a closely monitored radiological and clinical re-evaluation is of upmost importance. In a multidisciplinary approach the following critical points require consideration before a therapy is implemented,: size and location of the tumor, progression rate, genetic background, patient age and general condition, relevant comorbidities, the presence of synchronous PG and/or vasoactive catecholamine-producing tumors. Although best practice algorithms for the treatment of cervical PG have already been devised, recent innovative developments have led to more patient-tailored, individualized treatment approaches.

Update in the classification and the role of intra-arterial stenting in the management of carotid body paragangliomas

BACKGROUND

To review the Shamblin classification of carotid body paragangliomas (CBPs) and the role of intra-arterial stenting in their surgical management.

METHODS

Retrospective case series of 20 patients with 28 CBPs that were surgically resected at our center. Intra-arterial stenting was performed in Shamblin II and II classes.

RESULTS

The mean follow-up was 47.8 months. Five (17.9%) tumors were Shamblin class I, 15 (53.6%) were class II, and 8 (28.6%) were class III. Thirteen (68.4%) CBPs were associated with other paragangliomas. The internal carotid artery (ICA) was stented preoperatively in eight (28.6%) cases and occluded in four (14.3%) cases. The tumor extended to the jugular foramen in six cases (21.4%). Intraoperatively, there was an ICA injury in one case of Shamblin II CBP in the present era.

CONCLUSIONS

The proposed classification enables the clinician to plan the management of the ICA and the right approach. Stenting of the ICA gives a chance for complete tumor removal with arterial preservation.

65 YEARS OF THE DOUBLE HELIX: Genetics informs precision practice in the diagnosis and management of pheochromocytoma

Although the authors of the present review have contributed to genetic discoveries in the field of pheochromocytoma research, we can legitimately ask whether these advances have led to improvements in the diagnosis and management of patients with pheochromocytoma. The answer to this question is an emphatic Yes! In the field of molecular genetics, the well-established axiom that familial (genetic) pheochromocytoma represents 10% of all cases has been overturned, with >35% of cases now attributable to germline disease-causing mutations. Furthermore, genetic pheochromocytoma can now be grouped into five different clinical presentation types in the context of the ten known susceptibility genes for pheochromocytoma-associated syndromes. We now have the tools to diagnose patients with genetic pheochromocytoma, identify germline mutation carriers and to offer gene-informed medical management including enhanced surveillance and prevention. Clinically, we now treat an entire family of tumors of the paraganglia, with the exact phenotype varying by specific gene. In terms of detection and classification, simultaneous advances in biochemical detection and imaging localization have taken place, and the histopathology of the paraganglioma tumor family has been revised by immunohistochemical-genetic classification by gene-specific antibody immunohistochemistry. Treatment options have also been substantially enriched by the application of minimally invasive and adrenal-sparing surgery. Finally and most importantly, it is now widely recognized that patients with genetic pheochromocytoma/paraganglioma syndromes should be treated in specialized centers dedicated to the diagnosis, treatment and surveillance of this rare neoplasm.

Mathematical Models for Tumor Growth and the Reduction of Overtreatment

Background  To improve our understanding of the natural course of head and neck paragangliomas (HNPGL) and ultimately differentiate between cases that benefit from early treatment and those that are best left untreated, we studied the growth dynamics of 77 HNPGL managed with primary observation. Methods  Using digitally available magnetic resonance images, tumor volume was estimated at three time points. Subsequently, nonlinear least squares regression was used to fit seven mathematical models to the observed growth data. Goodness of fit was assessed with the coefficient of determination ( R ² ) and root-mean-squared error. The models were compared with Kruskal-Wallis one-way analysis of variance and subsequent post-hoc tests. In addition, the credibility of predictions (age at onset of neoplastic growth and estimated volume at age 90) was evaluated. Results  Equations generating sigmoidal-shaped growth curves (Gompertz, logistic, Spratt and Bertalanffy) provided a good fit (median R ² : 0.996-1.00) and better described the observed data compared with the linear, exponential, and Mendelsohn equations ( p  < 0.001). Although there was no statistically significant difference between the sigmoidal-shaped growth curves regarding the goodness of fit, a realistic age at onset and estimated volume at age 90 were most often predicted by the Bertalanffy model. Conclusions  Growth of HNPGL is best described by decelerating tumor growth laws, with a preference for the Bertalanffy model. To the best of our knowledge, this is the first time that this often-neglected model has been successfully fitted to clinically obtained growth data.

A meta-analysis on the surgical management of paraganglioma of the carotid body per Shamblin class

OBJECTIVE

The aim of this study was to evaluate the risk associated with different types of surgery for carotid body paraganglioma of different Shamblin class. A meta-analysis was conducted to evaluate per tumour class, the local control, cranial nerve damage and complication rates of different techniques using internal carotid artery (ICA) and external carotid artery (ECA) ligation, clamping or bypassing, as well as the craniocaudal vs caudocranial techniques.

DESIGN

A meta-analysis is conducted after a systematic search in PubMed and the Cochrane library, in accordance with the PRISMA guidelines.

MAIN OUTCOME MEASURES

Local control, cranial nerve damage, complications, function recovery.

RESULTS

Out of 3565 articles, 27 were selected. The overall quality of evidence of studies was low. Cranial nerve damage (3%, 17% and 39%) and complication rates (0%, 1% and 10%) were significantly related to Shamblin class (class 1, 2 and 3, respectively, P < .01). For class 3 tumours, an increased risk of complications was found associated with routine ICA manipulation/reconstruction (RR 3.12 with a 95% CI of 1.29-7.59), as well as a trend towards enhanced risk of routine ECA ligation (RR 3.48 with a 95% CI of 0.88-13.81).

CONCLUSIONS

For class 1 and 2 tumours, surgery seems a viable treatment option. For class 3 tumours, morbidity in terms of cranial nerve deficit and complications is considerable; particularly, the use of ICA manipulation/reconstruction and potentially ECA ligation seem to be accompanied by high stroke incidence.

Clinical progression and metachronous paragangliomas in a large cohort of SDHD germline variant carriers

Although it is well established that paternally transmitted germline variants in SDHD are associated with multifocal paragangliomas and lifelong follow-up is generally advised, the risk of metachronous lesions is presently unknown. In a large Dutch cohort of SDHD variant carriers, we studied the development of new paragangliomas, and the evolution of symptoms and cranial nerve impairment. Recurrent event analysis and the Kaplan-Meier product limit estimator were used to study the risk of new lesions. The relation between several predictors and development of new symptoms was assessed using logistic regression. Of the 222 SDHD variant carriers included, 65% presented with symptoms and 11% with cranial nerve dysfunction. Over a median period of 8 years, 42% reported new symptoms, and new cranial nerve impairment was observed in 11% of subjects. The estimated fraction of subjects that developed new HNPGL increased to 73% (95% CI: 52-85%) after 22 years of follow-up. Males were more likely to develop new HNPGL compared to females (HR: 1.63, 95% CI: 1.10-2.40), as were subjects that presented with symptoms, compared to subjects that were asymptomatic at baseline (HR: 1.61, 95% CI: 1.01-2.55). In addition, the risk of new lesions decreased with number of HNPGL present at first diagnosis (HR: 0.68 and 95% CI: 0.56-0.82). Carriers of a paternally inherited SDHD variant face a considerable risk for new HNPGL. In addition, nearly 50% of subjects reported new symptoms. However, new cranial nerve deficits were observed in only 11%, which is less than reported in surgical series. These risks should be taken into account when considering treatment strategies and counseling.

Translating carotid body function into clinical medicine

The carotid body (CB) is considered the main O₂ chemoreceptor, which contributes to cardiorespiratory homeostasis and ventilatory acclimatization. In clinical medicine, the most common pathologies associated with the CB are tumours. However, a growing body of evidence supports the novel idea that an enhanced CB chemosensory discharge contributes to the autonomic dysfunction and pathological consequences in obstructive sleep apnoea (OSA), hypertension, systolic heart failure (HF) and cardiometabolic diseases. Heightened CB chemosensory reactivity elicited by oxidative stress has been involved in sympathetic hyperactivity, cardiorespiratory instability, hypertension and insulin resistance. CB ablation, which reduces sympathetic hyperactivity, decreases hypertension in animal models of OSA and hypertension, eliminates breathing instability and improves animal survival in HF, and restores insulin tolerance in cardiometabolic models. Thus, data obtained from preclinical studies highlight the importance of the CB in the progression of sympathetic-related diseases, supporting the idea that appeasing the enhanced CB chemosensory drive may be useful in improving cardiovascular, respiratory and endocrine alterations. Accordingly, CB ablation has been proposed and used as a treatment for moderating resistant hypertension and HF-induced sympathetic hyperactivity in humans. First-in-human studies have shown that CB ablation reduces sympathetic overactivity, transiently reduces severe hypertension and improves quality of life in HF patients. Thus, CB ablation would be a useful therapy to reverse sympathetic overactivation in HF and severe hypertension, but caution is required before it is widely used due to the crucial physiological function played by the CB. Further studies in preclinical models are required to assess side-effects of CB ablation.

Clinical Characterization of the Pheochromocytoma and Paraganglioma Susceptibility Genes SDHA, TMEM127, MAX, and SDHAF2 for Gene-Informed Prevention

Importance

Effective cancer prevention is based on accurate molecular diagnosis and results of genetic family screening, genotype-informed risk assessment, and tailored strategies for early diagnosis. The expanding etiology for hereditary pheochromocytomas and paragangliomas has recently included SDHA, TMEM127, MAX, and SDHAF2 as susceptibility genes. Clinical management guidelines for patients with germline mutations in these 4 newly included genes are lacking.

Objective

To study the clinical spectra and age-related penetrance of individuals with mutations in the SDHA, TMEM127, MAX, and SDHAF2 genes.

Design, Setting, and Patients

This study analyzed the prospective, longitudinally followed up European-American-Asian Pheochromocytoma-Paraganglioma Registry for prevalence of SDHA, TMEM127, MAX, and SDHAF2 germline mutation carriers from 1993 to 2016. Genetic predictive testing and clinical investigation by imaging from neck to pelvis was offered to mutation-positive registrants and their relatives to clinically characterize the pheochromocytoma/paraganglioma diseases associated with mutations of the 4 new genes.

Main Outcomes and Measures

Prevalence and spectra of germline mutations in the SDHA, TMEM127, MAX, and SDHAF2 genes were assessed. The clinical features of SDHA, TMEM127, MAX, and SDHAF2 disease were characterized.

Results

Of 972 unrelated registrants without mutations in the classic pheochromocytoma- and paraganglioma-associated genes (632 female [65.0%] and 340 male [35.0%]; age range, 8-80; mean [SD] age, 41.0 [13.3] years), 58 (6.0%) carried germline mutations of interest, including 29 SDHA, 20 TMEM127, 8 MAX, and 1 SDHAF2. Fifty-three of 58 patients (91%) had familial, multiple, extra-adrenal, and/or malignant tumors and/or were younger than 40 years. Newly uncovered are 7 of 63 (11%) malignant pheochromocytomas and paragangliomas in SDHA and TMEM127 disease. SDHA disease occurred as early as 8 years of age. Extra-adrenal tumors occurred in 28 mutation carriers (48%) and in 23 of 29 SDHA mutation carriers (79%), particularly with head and neck paraganglioma. MAX disease occurred almost exclusively in the adrenal glands with frequently bilateral tumors. Penetrance in the largest subset, SDHA carriers, was 39% at 40 years of age and is statistically different in index patients (45%) vs mutation-carrying relatives (13%; P < .001).

Conclusions and Relevance

The SDHA, TMEM127, MAX, and SDHAF2 genes may contribute to hereditary pheochromocytoma and paraganglioma. Genetic testing is recommended in patients at clinically high risk if the classic genes are mutation negative. Gene-specific prevention and/or early detection requires regular, systematic whole-body investigation.

Age and Tumor Volume Predict Growth of Carotid and Vagal Body Paragangliomas

Objective  Treatment for head and neck paragangliomas (HNGPL) can be more harmful than the disease. After diagnosis, an initial period of surveillance is often indicated, and surgery or radiotherapy is reserved for progressive disease. With the aim to optimize this "wait and scan" strategy, we studied growth and possible predictors. Design  A retrospective cohort study was conducted. Setting  This study was conducted at a tertiary referral center for patients with HNGPL. Methods  Tumor volume was estimated for 184 SDHD -related carotid and vagal body paragangliomas using sequential magnetic resonance imaging. Cox regression was used to study predictors of tumor growth. Results  The estimated fraction of growing tumors ranged from 0.42 after 1 year of follow-up to 0.85 after 11 years. A median growth rate of 10.4 and 12.0% per year was observed for carotid and vagal body tumors, respectively. Tumor location, initial volume, and age ( p  < 0.05) were included in our prediction model. The probability of growth decreased with increasing age and volume, indicating a decelerating growth pattern. Conclusions  We created a prediction model (available online), enabling a more individualized "wait and scan" strategy. The favorable natural course of carotid and vagal body paragangliomas was confirmed; although with long follow-up growth will be observed in most cases.

Diagnosis and surgical treatment of carotid body tumor: A retrospective analysis of 58 patients

The aim of the present study was to illustrate the diagnosis and treatment of carotid body tumor (CBT) based on our experience of previous patients. A total of 58 patients (62 lesions) with CBT who received surgery between October 2003 and October 2013 were included. In total, 17 lesions were categorized into Shamblin grade I, 33 were grade II, and 12 were grade III. Surgical resection of CBT was performed for 52 lesions, resection of CBT and the external carotid artery was performed for 9 lesions, and resection of CBT and the internal carotid artery was performed for 1 lesion. No hemiplegia was observed. Hoarseness and bucking were observed in 2 patients of Shamblin grade III, and were eliminated 1 month subsequent to the administration of hormone therapy and a nerve-nurturing strategy. No relapse or mortality was observed during the follow-up. In conclusion, surgical resection of CBT is recommended following diagnosis. The evaluation of imaging features and cerebral collateral circulation is important for treatment.

Acute onset of paraganglioma of filum terminale: A case report and surgical treatment

•

A very rare case of paraganglioma of filum terminale is described.

•

Clinical and radiological features of spinal paraganglioma are listed.

•

Surgical management of paraganglioma of filum terminale is discussed.

Introduction

Paragangliomas of filum terminale are rare benign tumors, arising from the adrenal medulla or extra-adrenal paraganglia. These lesions usually present with chronic back pain and radiculopathy and only two cases of acute neurological deficit have been reported in literature.

Presentation of case

A case with an acute paraplegia and cauda equina syndrome due to an hemorrhagic paraganglioma of the filum terminale is described. Magnetic resonance imaging showed an intradural tumor extending from L1 to L2 compressing the cauda equina, with an intralesional and intradural bleed. An emergent laminectomy with total removal of the tumor was performed allowing a post-operative partial sensory recovery. Histopathological examination diagnosed paraganglioma.

Discussion

Paragangliomas are solid, slow growing tumors arising from specialized neural crest cells, mostly occurring in the head and neck and rarely in cauda equina or filum terminale. MRI is gold standard radiological for diagnosis and follow-up of these lesions. They have no pathognomonic radiological and clinical features and are frequently misdiagnosed as other spinal lesions. No significant correlation was observed between the duration of symptoms and tumor dimension. Acute presentation is unusual and emergent surgical treatment is fondamental. The outcome is very good after complete excision and radiotherapical treatment is recommended after an incomplete resection. Conclusion: Early radiological assessment and timely surgery are mandatory to avoid progressive neurological deficits in case of acute clinical manifestation of paraganglioma of filum terminale.