Vagal Paragangliomas Research Articles

Atypical Presentation and Postoperative Management of Vagal Nerve Tumors.

Tumors involving the vagus nerve are often clinically silent. We offer a case series with different clinical presentations and distinctive post-surgical sequelae that highlight some of the challenges associated with managing cervical vagal nerve tumors. Single-institution, retrospective review of patients with tumors involving the vagus nerve. We describe clinical presentations and postoperative sequelae of five patients who underwent surgical management of vagal nerve pathology with atypical presentation or subsequent clinical course. Here, we present five patients treated at our institution for vagal tumors. In four of the five patients, the presenting symptoms resolved after surgery. Two patients presented with intractable neurogenic cough, and another two presented with autonomic symptoms, one with syncope/palpitations and the other with intractable sweating. The final patient presented with a rapidly enlarging vagal paraganglioma and developed intractable cough after resection. We present two patients with novel approach to vagal paragangliomas that underwent ligation of feeding blood supply without removing the tumor, resulting in resolution of an intractable cough in one patient and resolution of severe nighttime sweating in the other. Management of tumors associated with the cervical vagus nerve that present with symptoms or rapid growth poses a clinical dilemma. Consideration of the tumor origin with either enucleation of schwannomas or ligation of feeding vessels may preserve function while addressing the presenting symptoms.

Management of bilateral head and neck paragangliomas at a single-institution across four decades.

Bilateral head and neck paragangliomas (HNPGLs) require nuanced management to balance tumor control with functional preservation. All patients seen at a single-institution for bilateral paraganglioma between 1983 and 2023 were retrospectively reviewed. Demographics, genetic testing results, and tumor characteristics were analyzed and compared to treatment modality and cranial nerve outcomes. There were 49 patients with 116 tumors (90 carotid body tumors [CBTs], 15 vagal paragangliomas [VPs], and 11 jugular paragangliomas [JPs]). Twenty-six patients had SDH pathologic variants (PV). Surgical management was more commonly utilized in younger patients (OR: 0.97, 95% CI: 0.950-0.992) and for JPs (OR: 9, 95% CI: 1.386-58.443). In surgical cases, CBTs had a lower risk of postoperative cranial nerve deficits compared to JPs and VPs (OR: 0.095, 95% CI: 0.013-0.692). Younger patients with bilateral HNPGLs, especially those with JP and CBT, are more often treated with surgery. CBTs have lowest risk of cranial nerve deficits after surgery.

The Role of Internal Carotid Artery Stent in the Management of Skull Base Paragangliomas.

Background: After two decades from its introduction in the lateral skull base paraganglioma surgery, the indications and results of preoperative internal carotid artery stenting should be critically assessed. Materials and Methods: Monocentric retrospective study on 26 patients affected by head and neck paragangliomas (19 tympanojugular paragangliomas, 4 carotid body paragangliomas, 3 vagal paragangliomas) preoperatively treated with internal carotid artery stents between 2008 and 2023. The preoperative findings, the intraoperative complications and the final surgical results were analyzed. Results: The stent complication rate was less than 3.1%. Self-expanding highly flexible intracranial nitinol stents were applied. In all cases, it was possible to completely mobilize the internal carotid artery and perform a vascular dissection of the tumor. Gross total tumor resection was possible in 85% of cases. The median follow up was 7.83 y (SD +/- 3.93 y). No local recurrence was observed. Conclusions: The preoperative vascular stent facilitates tumor dissection from the internal carotid artery without risk of vascular damage, helping the surgeon to achieve surgical radicality. The vascular stent is indicated in the case of revision surgeries, circumferential involvement of the vessel and in cases with non-insufficient intracerebral crossflow. Procedural complications, temporary antiplatelet therapy and delay of surgery are the limitations of the procedure.

Endovascular Embolization as a Stand-Alone Treatment of Head and Neck Paragangliomas with Long-Term Tumor Control.

The impact of therapeutic embolization as a stand-alone treatment of head and neck paragangliomas considered surgically high-risk remains insufficiently understood. The aim of this study was to investigate the procedural risks and long-term volumetric development in head and neck paragangliomas with high surgical risk following therapeutic endovascular embolization as a stand-alone treatment. A retrospective database review of patients who underwent endovascular embolization as primary treatment for head and neck paragangliomas lacking appropriate curative treatment options at our institution (from January 2000 to February 2023) was conducted. Tumor volumetric analyses were performed before embolization and during follow-up. To assess the changes in tumor volume over time, the measurements were performed after embolization, first at 6 months and then on a yearly basis up to 6 years (mean follow-up time was 33.7 ± 24.4 months). Subgroup analyses were conducted for vagal and jugular/jugulotympanic paragangliomas. A total of 32 head and neck paragangliomas in 28 patients (mean age, 56.1 years ± 16.5 [standard deviation]; 18 female) with therapeutic embolization as stand-alone treatment were evaluated, of which 11 were vagal paragangliomas, 15 jugular/jugulotympanic paragangliomas, and 6 carotid body tumors. After a mean follow-up duration of 33.7 ± 24.4 months, tumor control was achieved in 75%, with significant median tumor volume reduction at 6 months (P = .02, n = 21). Vagal paragangliomas responded the most to embolization with a significantly decreased median volume from 22.32 cm3 to 19.09 cm3 (P = .008, n = 8). Transient complications occurred in 3.4%. Therapeutic embolization as a stand-alone treatment offers a low-risk control of tumor growth in surgically high-risk lesions, with a significant reduction in tumor volume after treatment. Among the different subtypes, vagal paragangliomas exhibited the strongest and longest regression of the tumor volume.

High Altitude Head and Neck Paragangliomas: A First Sub-Himalayan Experience.

High-altitude natives have a high incidence of parangangliomas (PGL) of the head and neck, especially the carotid body tumor. The aim of this study is to describe the clinical presentation, pattern, altitude of residence, distribution, management, and follow-up of head and neck paragangliomas (HNPGL) in our sub-Himalayan population. Retrospective cohort study. Academic tertiary care hospital. Hospital records of 20 patients of HNPGL diagnosed from December 2017 to December 2021 were retrieved for analysis. Twenty patients with 23 HNPGL, with a mean age of 41.74 years were managed in our institute. The female-to-male ratio was 2.3: 1 and the mean follow-up was 29.95 months. Nine had carotid body (CBPGL), 7 had tympanic (TPGL), 2 had jugular (JPGL), and 2 had vagal paragangliomas (VPGL). Multiple PGL were seen in 4 patients (20%). Majority of cases (all CBPGL and 57.14% of TPGL) were residents of the high altitude, and the rest were from the low altitude. Fifteen patients (8 CBPGL, 7 TPGL) were operated. There were no major complications except in a patient with large carotid body tumor required anastomosis of carotid artery. Five patients received stereotactic radiotherapy, and 1 malignant PGL received chemoradiotherapy. In this study, JPGL and VPGL are common at low altitudes, whereas carotid body and tympanic PGL were the most common tumor at high altitudes. Being a retrospective and study small sample size, a definite conclusion is not established, however, a genetic analysis and inclusion of a wider population in a future prospective study may establish the hypothesis.

Possibilities of ultrasound diagnostics of paragangliomas of the neck

The purpose of the study is to evaluate the results of ultrasound examination, generalize the criteria for differential diagnosis of various types of paragangliomas in neck area and the development of a standard ultrasound protocol that provides information about the resectability of formations.Material and methods. 91 patients (100 tumors) with a clinical diagnosis of neurogenic neck tumor were examined, of which 71 (71%) were carotid paragangliomas, 18 (18%) – vagal paragangliomas, 10 (10%) – neurinomas and 1 (1%) – neurofibroma. All patients underwent ultrasound examination, including examination of the tumor structure in B-mode, assessment of the size and prevalence formations relative to the base of the skull and color Doppler mapping to assess the degree of intra-tumor blood flow and the relationship of formations with carotid arteries.The study allowed us to systematize the main ultrasound signs characteristic of various neurogenic neck tumors, among which we identified: clear, even contours; the presence of a capsule; a heterogeneous, predominantly hypoechoic structure with hyperechoic inclusions resembling “salt–pepper”. The following parameters played a crucial role in differential diagnosis: localization of formation, features of intra-tumor blood flow and the relationship of paragangliomas with carotid arteries.Results. Evaluation of the structural features of the tumor in the B-mode did not show significant differences between various paragangliomas, neurinomas and neurofibromas, all formations had clear, even contours, their capsule was clearly visualized. For carotid paragangliomas in all 71 (100%) observations, the characteristic feature was the location in the bifurcation area of the common carotid artery, with the mouths of the internal and external carotid arteries moving apart, which was 100% the diagnostic criterion of this group of formations. Vagal paragangliomas or neurinomas in all cases were located outside the bifurcation of the carotid artery, although in close proximity to the carotid arteries. The nature and degree of intra–tumor vasularization is another argument in the differential diagnosis of paragangliomas, which, unlike other neurogenic tumors, are highly vascularized tumors. The study of the nature of the intracellular blood flow showed that arterial paragangliomas predominate vessels, unlike neurinomas and neurofibromas, have significantly poorer vascularization with a predominance of venous vessels in the structure of the tumor. In 8 (44%) cases, vagal paragangliomas sprouted into the adventitia of the carotid arteries, which was characterized by a local increase in blood flow in this area in combination with turbulence during ultrasound.Conclusion. The proposed algorithm of ultrasound examination of neurogenic formations in the neck area makes it possible already at the primary stage instrumental diagnostics to identify volumetric formations, differentiate them between themselves and with other neck formations and to assume the degree of traumatism of the proposed surgical intervention.

SDHx mutations are associated with the PI3K-Akt signaling pathway in vagal paragangliomas

Background: Vagal paraganglioma (VPGL) is a very rare neuroendocrine tumor arising from the paraganglion associated with the vagus nerve. VPGL is mainly characterized by an asymptomatic course and slow growth. However, up to 19% of tumors can metastasize. Due to the rarity of this tumor, information about VPGL is limited to single cases and small sample sets; the data on molecular genetic features is extremely scarce. Methods: For the first time we have analyzed the enrichment of biological pathways associated with mutations in the SDHx genes in VPGLs. Bioinformatics analysis was performed based on the results of high-throughput transcriptome sequencing on an Illumina platform for 33 tumor tissues obtained from patients with vagal paragangliomas. Results: Eight pathways of the Kyoto Encyclopedia of Genes and Genomes (KEGG) database with gene overrepresentation (top-40 mode) have been identified. Significant changes were shown for the cancer-associated PI3K-Akt signaling pathway and interconnected pathways of focal adhesion and interaction of receptors with the extracellular matrix enriched by overexpressed genes. Conclusion: Our result indicates the association of SDHx mutations with changes in the PI3K-Akt signaling pathway in vagal paraganglioma. The potential mechanism of deregulation in this pathway could be linked with a state of pseudohypoxia induced by the dysfunction of succinate dehydrogenase due to mutations in the SDHx genes.

Paragangliomas, Etiology, Review of 1070 Series of Cases Hospital De Especialidades Centro Médico La Raza

Objective: Present the frequency of atypical histological lineage paragangliomas on a third level hospital. Introduction: Paragangliomas, also known as neuroendocrine tumors, are rare and can appear in distinct places throughout the human body where chromaffin cells are present. Such examples include blood vessels and nerves. Thirty percent are in head and neck compartments; after carotid paragangliomas, the yugulotimpanic follow in frequency and then the vagal ones by 5%. Onlyone percent of paragangliomas located in the head and neck are functional compared with those located in other parts of the body that tend to be functional, most commonly causing hypertension. Methods: An ambispective, observational, descriptive review was conducted, including patients operated on by paraganglioma from 1987 to January 2023; 99.4% were initially diagnosed as carotid origin. Results: A total of 1070 patients were captured. 998 patients were female (93.2%). 1,063 of paragangliomas were carotid (99.3%), 2 were vagal (0.18%), 1 was yugulotympanic (0.09%) and 3 were in other locations (0.28%). One was reported as a Schwannoma. None of the tumors were reported as being hyperfunctional. Conclusion: The angiographic visualization of these lesions can confuse their diagnosis and cause an erroneous follow-up with a poor prognosis, since it is described that vagal paragangliomas recur in 17%.

Management of Complex Jugular Paragangliomas: Surgical Resection and Outcomes.

This study aimed to review tumor control and cranial nerve function outcomes in patients with complex jugular paragangliomas and to refine the surgical strategies for complex jugular paragangliomas. We describe our experience with 12 patients with complex jugular paragangliomas diagnosed in our institution from January 2013 to June 2020. The main outcomes included tumor control, complications, and function of facial nerve and lower cranial nerves, postoperatively. Gross-total resection was achieved for 9 (75%) patients, and subtotal resection was achieved for 3 (25%) patients. The surgical tumor control rate was 100% after a mean follow-up of 45.5 months (range, 13-111 months). Postoperatively, 10 patients (83.3%) obtained unchanged or improved facial nerve function. However, new lower cranial nerve deficits occurred in 2 patients (16.7%) due to surgical removal of the concurrent vagal paraganglioma and scar tissue enclosing the IX and XII nerves. Our refined surgical techniques, including tension-free anterior facial nerve rerouting, sigmoid sinus tunnel-packing, and pushpacking techniques, could be a choice for the treatment of complex jugular paragangliomas to achieve tumor control and cranial nerves preservation. A 2-stage surgery should be applied to minimize the risk of bilateral cranial neuropathies and the influence on cerebral circulation in patients with bilateral paragangliomas. The preoperative endovascular intervention such as coil embolization or internal carotid artery stenting can be employed for the management of paragangliomas with internal carotid artery-associated lesions.

Vagal paraganglioma extending to the brain: a case report with literature review

Introduction: Vagal paraganglioma (VP) is a rare tumor of the vagus nerve (VII). This study aims to present a rare case of VP extending to the brain. Case report: A 35-year-old woman presents with neck swelling for 1 year. On examination, there was an ill-defined hard mass involving the left side of the anterior neck, fixed in all directions. A neck ultrasound revealed an irregular mass attached to both carotid arteries. A computed tomography scan showed a large lobulated, intensely enhanced mass encasing left carotid carotid vessels. Total resection under general anesthesia was done. Histopathologic examination revealed VP. Discussion: VP is the rarest form of paraganglioma and accounts for <5% of all head and neck paragangliomas. The average age of diagnosis for these patients is reported to be 45 years. VP poses a therapeutic challenge due to its anatomic location, and surgery is often associated with a significant rate of postoperative morbidities, particularly loss or impaired vagus nerve function. Conclusion: VP is a rare tumor of the head and neck, even rarer in young adults. A standard management approach is absent for these cases.

Long-Term Outcomes in Head and Neck Paragangliomas Managed with Intensity-Modulated Radiotherapy.

Head & Neck Paragangliomas have been historically relying on surgery mostly, with worsened quality of life and major sequelae. Conventional external radiation therapy seems to offer an equivalent control rate with a low toxicity profile. The aim of this study was to assess the safety and efficiency of intensity-modulated radiation therapy in Head & Neck paragangliomas. This is a retrospective monocentric study conducted in a referral center, including all patients treated with IMRT, whether as an exclusive or post-operative treatment for a tympanic and jugular, carotid, or vagal paraganglioma. Data collection was performed through the manuscript and computerized medical files, including consultation, operative, imaging, pathological analyses, delineation, and treatment planning reports. Success was defined as the complete or partial regression or stabilization without progression, or relapse in accordance with the RECIST criteria. Acute toxicities and long-term sequelae were assessed. Our cohort included 39 patients included between 2011 and 2021: 18 patients treated for a TJ PG (45.9%), 11 patients for a carotid PG (28.4%), and 9 for a vagal PG (23.1%). Twenty-nine patients had IMRT as an exclusive treatment (74.4%), whereas 10 patients had a post-operative complementary treatment (25.6%). Median follow-up in our cohort was 2318 days (average=2200 days, 237-5690, sd=1281.9). Among 39 patients, 37 were successfully controlled with IMRT (94.8%), and the toxicity profile was low without any major toxicity. IMRT seems an ideal treatment, whether exclusive or post-operative for Head & Neck paragangliomas. 3 Laryngoscope, 133:607-614, 2023.

Paragangliomas da Cabeça e Pescoço: A Experiência de um Centro Oncológico do Sul da Europa

Paragangliomas are usually benign slow-growing tumors, but they are locally invasive and can cause significant morbidity. The aim of this study was to characterize the presenting symptoms, secretory status, genetics, imaging features, treatment modalities, post-treatment complications and survival of patients with head and neck paragangliomas treated at a single institution. We retrospectively reviewed the clinical records of patients managed at our center between 1997 and 2020. Seventy-three patients were included in the study, encompassing 89 head and neck paragangliomas. Forty-eight patients (65.8%) were female and 15 (20.5%) had multiple tumor sites (including 10 patients with multicentric benign paragangliomas and five with disseminated malignant disease). Regarding location, our series encompassed 40 temporal bone paragangliomas (44.9%), 24 carotid body paragangliomas (27%), 22 vagal paragangliomas (24.7%), two laryngeal paragangliomas (2.2%) and one sinonasal paraganglioma (1.1%). Excessive catecholamine secretion was detected in 11 patients (15.1%). Sixty-four patients (87.7%) underwent genetic testing. Of those, 24 (37.5%) exhibited pathogenic succinate dehydrogenase complex germline mutations. Regarding patients who presented with untreated disease, 45 patients (66.2%), encompassing 55 tumors, underwent surgery as primary treatment modality, 20 (29.4%; 23 tumors) were initially treated with radiotherapy and three patients (4.4%, encompassing three solitary tumors) were kept solely under watchful waiting. Five-year overall survival was 94.9% and disease-free survival was 31.9%. Head and neck paragangliomas are rare, slow-growing but locally aggressive tumors resulting in high morbidity but low mortality rates.

An Overview of Vagal Paraganglioma Surgery: Evaluation of Operative Morbidities and Quality of Life After Surgery

An Overview of Vagal Paraganglioma Surgery: Evaluation of Operative Morbidities and Quality of Life After Surgery

Vagal Paraganglioma of Neck Mimicking Carotid Body Tumor: Clues to Differentiate on Imaging.

Paragangliomas of the head and neck can arise in many locations along the carotid sheath and middle ear. A hypervascular tumor in relation to the major cervical vessels can be either a carotid body tumor or vagal paraganglioma. Carotid bifurcation separation is a characteristic feature of carotid body tumours. We present a case of vagal paraganglioma of the neck, causing carotid bifurcation separation similar to that of a carotid body tumor. In this case report, we highlight the imaging features that can differentiate these two paragangliomas in such a confusing situation.

Head and Neck Malignant Paragangliomas: Experience from a Single Institution.

Objectives: To summarize the clinicopathological and genetic features of malignant paragangliomas in head and neck cancer and to explore the appropriate treatment options for this rare lesion. Methods: Six patients harboring head and neck malignant paraganglioma from Beijing Tongren Hospital were retrospectively reviewed. The clinicopathological characteristics, gene mutations, and prognosis of these patients were analyzed. Results: Of these 6 patients, 3 were male and 3 were female; 4 patients harbored malignant carotid body tumors, and two had malignant vagal paragangliomas. Three patients had cervical lymph node metastasis, two presented with lung and bone metastasis, and 1 had lung and liver metastasis. Of the 6 patients, four underwent surgical resection, and the other two patients denied surgery and instead received chemotherapy with paclitaxel, ifosfamide, and dacarbazine. These 2 patients with vagal paraganglioma received postoperative radiotherapy. All 6 patients are still alive at the present time, with a median follow-up time of 66months. Positive Ki-67 expression in tumor tissue ranged from 1% to 40%. Genetic mutations in SDHD, SDHB, ATR, and MAP3K13 were identified in 4 patients. Conclusions: After comprehensive treatment, head and neck malignant paraganglioma can attain a favorable prognosis. Genetic mutations are commonly detected in patients with malignant paragangliomas. This study also identified mutations in ATR and MAP3K13 in these patients.

Head and neck paragangliomas: Ten years of experience in a third health center. A cohort study

Head and neck paragangliomas are rare vascular tumors derived from the paraganglionic system, located at the carotid body, jugular vein, tympanic cavity and vagal nerve.From 2010 to 2020, a cohort of 26 patients divided in two groups, 15 with cervical paragangliomas and 11 with temporal bone paragangliomas, was reviewed by analysing the medical history, the epidemiological and clinical parameters, the imaging results and classification, the modality of treatment and outcome.Cervical paragangliomas present as firm and pulsatile mass with the characteristic aspect of “salt and pepper” on MRI T1 weighted sequences. The most common type on Shamblin classification was the type II. Total surgical resection was performed in 93,33% of cases. The sensitivity of MRI in the diagnosis of vagal paragangliomas was up to 75%, with a specificity of 90,91% and the correlation of the MRI results and the findings of surgical exploration is significant with p ⩽ 0.02.Temporal bone paragangliomas appear as pulsatile mass behind the tympanic membrane, causing variable hearing loss in 90,90% of the cases. The facial nerve is the most frequently affected cranial nerve, in 36,36% of the cases. The main type according to FISH classification is the type B. Embolization was performed in all type C tumors. Surgery was the first line treatment while the inoperable patients were considered for radiotherapy.The aim of this study is to report the main clinical features of head and neck paragangliomas, the imaging tools and findings evaluating their sensitivity and specificity and the treatment protocol and outcome.

Functional Outcomes Following Delayed Laryngeal Reinnervation Of Patients with Vagal Paralysis After Paraganglioma and Schwannoma Surgery

We present a prospective case series that aimed to report the functional (voice and swallowing) outcomes of delayed laryngeal reinnervation following vagal interruption by resection of vagal paraganglioma and schwannoma. A dedicated, anonymized database was established in 2012 with a minimum eighteen-month follow up set for this report. Internationally validated self- and observer-reported measures were recorded preoperatively and at six, 12 and, 18 months together with demographics, diagnoses, and operative details. A total of eight patients with a median age of 46 (37-54) underwent excision of vagal paraganglioma (five) and schwannoma (three) with few mild complications. Three underwent selective and five non selective reinnervation. Seven out of eight patients underwent synchronous injection medialization. The voice handicap index (VHI-30) improved from a baseline median 83 (range 52-102) to 7.5 (5-58) at 18 months; maximum phonation time improved from median 8 (range 5-15) to 10.5 (8.5-11); voice grade ("G" in grade, roughness, breathiness, asthenia, and strain [GRBAS] scoring) improved from median three (severe impairment, range 0-3) to one (mild impairment, 0-2); Eating Assessment Tool (EAT-10) score improved from median 12 (range 3.5-27) preoperatively to one (0-16); and reflux symptom index (RSI) improved from median 25 (range 17-36) to 7 (0-36). One patient exhibited no discernible reinnervation, while the remainder exhibited good cord bulk and tone, though without purposive abduction. Delayed laryngeal reinnervation for high vagal paralysis is a safe technique associated with good voice and swallowing outcomes by 12-18 months. Potential confounders in this small series and the absence of a control arm both limit conclusions, but this study suggests that further prospective, controlled studies, and/or case registration are merited.

Management of Multiple Head and Neck Paragangliomas With Assistance of a 3-D Model.

Extirpation of multiple head and neck paragangliomas carries challenge due to close anatomic relationships with critical neurovascular bundles. This study aims to assess whether the application of 3-D models can assist with surgical planning and treatment of these paragangliomas, decrease surgically related morbidity and mortality. Fourteen patients undergoing surgical resection of multiple head and neck paragangliomas were enrolled in this study. A preoperative 3-D model was created based on radiologic data, and relevant critical anatomic relationships were preoperatively assessed and intraoperatively validated. All 14 patients presented with multiple head and neck paragangliomas, including bilateral carotid body tumors (CBT, n = 9), concurrent CBT with glomus jugulare tumors (GJT, n = 4), and multiple vagal paragangliomas (n = 1). Ten patients underwent genomic analysis and all harbored succinate dehydrogenase complex subunit D (SDHD) mutations. Under guidance of the 3-D model, the internal carotid artery (ICA) was circumferentially encased by tumor on 5 of the operated sides, in 4 (80%) of which the tumor was successfully dissected out from the ICA, whereas ICA reconstruction was required on one side (20%). Following removal of CBT, anterior rerouting of the facial nerve was avoided in 3 (75%) of 4 patients during the extirpation of GJT with assistance of a 3-D model. Two patients developed permanent postoperative vocal cord paralysis. There was no vessel rupture or mortality in this study cohort. The 3-D model is beneficial for establishment of a preoperative strategy, as well as planning and guiding the intraoperative procedure for resection of multiple head and neck paragangliomas.

Mutation Frequency in Main Susceptibility Genes Among Patients With Head and Neck Paragangliomas.

Head and neck paragangliomas (HNPGLs) are rare neuroendocrine tumors that have a high degree of heritability and are predominantly associated with mutations in ten genes, such as SDHx, SDHAF2, VHL, RET, NF1, TMEM127, MAX, FH, MEN2, and SLC25A11. Elucidating the mutation prevalence is crucial for the development of genetic testing. In this study, we identified pathogenic/likely pathogenic variants in the main susceptibility genes in 102 Russian patients with HNPGLs (82 carotid and 23 vagal paragangliomas) using whole exome sequencing. Pathogenic/likely pathogenic variants were detected in 43% (44/102) of patients. We identified the following variant distribution of the tested genes: SDHA (1%), SDHB (10%), SDHC (5%), SDHD (24.5%), and RET (5%). SDHD variants were observed in the majority of the patients with bilateral/multiple paragangliomas. Thus, among Russian patients with HNPGLs the most frequently mutated gene was SDHD followed by SDHB, SDHC, RET, and SDHA.

Surgical Candidacy in Skull Base Paragangliomas: An Institutional Experience.

Objective The aim of the study is to determine the surgical candidacy and nuances of skull base paraganglioma surgery in the era of radiotherapy. Materials and Methods This was a retrospective observational study conducted in patients who presented with skull base paragangliomas between January 2017 and December 2019. Primary data, including indication for surgery, the approach used, the extent of resection, complications, and postoperative lower cranial nerve status were studied. Results A total of 21 cases of skull base paragangliomas were analyzed, including seven cases of tympanic paraganglioma, 10 cases of jugular foramen paraganglioma, three cases of multiple paragangliomas, and one case of vagal paraganglioma. Indications for surgery were young age, bleeding from ear, neck mass with upper aerodigestive pressure symptoms, lower cranial nerve paralysis, and patients with intracranial pressure symptoms. Total excision was done in 11 patients, near-total excision in five patients, subtotal in three patients, and surgery was not done in two patients. Facial nerve paralysis was the most common complication observed, followed by bleeding and flap necrosis. Radiotherapy was considered as adjuvant treatment wherever indicated. Conclusion A thorough knowledge and understanding of the pathophysiology of the skull base paragangliomas and its management strategies can help to achieve excellent results in terms of tumor clearance and reduction in complications. A multidisciplinary team approach and meticulous skull base surgical techniques have a significant role to play in the management of paragangliomas, especially in developing countries where availability of radiosurgery is still a challenge.