Bilateral Carotid Body Tumors Research Articles

Fifteen Years of Experience with Surgical Management of Bilateral Non-familial Carotid Body Tumors

Bilateral carotid body tumors (CBTs) clinical manifestation is infrequent. We conducted this work to describe our experience in the surgical treatment of bilateral CBT and to analyze our results. A retrospective, observational study. We analyzed the totality of bilateral CBT resections that had been performed in our institution from January 2008 to September 2023. Data was obtained from medical records and anonymized, ethics approval was obtained from our institution committee. As the number of observations was less than those required by the central limit theorem our sample was considered nonparametric. Statistical analysis was performed on Stata17. We evaluated 16 patients with a total of 32 CBT; surgical resection was performed in 28 cases (87.50%). Median age of the patients was 60years (interquartile range [IQR] 46-64). Regarding the Shamblin classification, 9 CBTs (32.14%) were classified as Shamblin I, 11 (39.29%) as Shamblin II, and 8 (28.57%) as Shamblin III. The median Distance to the Base of the Skull (DTBOS) was 3.5cm (IQR 2.7-5.1), and the median tumor volume was 11.25cc (IQR 3.4-18.7). The median bleeding volume was 300ml (IQR 200-500), and the median surgical time was 190min (IQR 145-240). All surgeries were performed using the Retrocarotid Dissection technique. We documented 9 (32.14%) cases of nerve injuries, all of which were transitory. In the median regression a statistically significant association was found between DTBOS, Shamblin classification and tumor volume with intraoperative bleeding and length of stay. Surgical treatment remains safe and should be considered the gold standard for accurate histologic diagnosis. DTBOS and tumor volume, in addition to Shamblin classification, must be considered in preoperative planning to predict bleeding and hospital stay.

FRI368 Thyroid Paraganglioma: A Rare Manifestation Of Paraganglioma Syndrome Associated With SDHD Mutation

Abstract Disclosure: K. Samuel: None. C. McMullen: None. C. Veloski: None. S. Kushchayev: None. J.E. Hallanger-Johnson: None. J. Hernandez Prera: None. J. Muzaffar: None. G.Q. Yang: None. V. Tarasova: None. Background: Thyroid paragangliomas (TP) are exceptionally rare, representing 0.5% of all paragangliomas (PGL) with total of less than 70 cases reported to date. We report a case of a TP presenting with an indeterminate thyroid nodule, as a first manifestation of multifocal head and neck PGL, associated with succinate dehydrogenase complex subunit D (SDHD) mutation. Clinical case: A 59-year female was initially seen at the tertiary referral center for an indeterminate thyroid nodule discovered incidentally on neck ultrasound (US) ordered for evaluation of a palpable posterior left neck mass. Neck/thyroid US showed multiple nonspecific bilateral lymph nodes measuring up to 1.2 cm and a 1.7 cm right interpolar markedly hypoechoic and hypervascular solid thyroid nodule (TR5). Clinically, the patient did not have symptoms related to the thyroid nodules or lymph nodes in the neck. Thyroid function tests were within normal range. An US-guided FNA biopsy was nondiagnostic. Core biopsy was suspicious for papillary thyroid carcinoma (hypercellular thyroid parenchyma with some follicular cells with nuclear irregularity, grooves, and hyperchromasia). Pathology slides review at the tertiary center showed nondiagnostic sample (Bethesda I) on cytopathology and neuroendocrine neoplasm consistent with PGL on core biopsy (immunohistochemical stains showed tumor cells positive for synaptophysin, chromogranin and GATA3. TTF1, TG, calcitonin, CEA and AE1/3 negative). US of the neck/thyroid 4 months later showed stable disease. Calcitonin and 24-h urinary catecholamines, metanephrines were within normal limits. There was no family history of pheochromocytoma or PGL. Genetic testing showed germline SDHD mutation (p.P81L(c.242c>5). 68Ga-DOTATATE PET/CT revealed multifocal areas of increased somatostatin receptor expression from the skull base to the left thoracic inlet, which included right and left skull base lesions, left neck level IIA lymph node, right and left level III lymph nodes, right thyroid lobe lesion, and left prevascular superior mediastinal lesion. An MRI of the brain and neck with and without contrast showed 1.7 cm right jugular, 0.6 cm right carotid, and 0.6 cm left vagal PGL, 1.3 cm right thyroid nodule, left level II 1.1x.6 cm lymphadenopathy, and 0.4 cm left superior mediastinal nodule. A CT of the neck w/contrast showed multiple areas likely representing bilateral carotid body tumors, left vagal PGL, right glomus jugular, and thyroid PGL stable over 6 months. MIBG nuclear medicine scan revealed no radiotracer accumulation in the lesions. EBRT therapy is planned to the skull base lesion. Conclusions: TP should be considered in the differential diagnosis of hypervascular thyroid nodules in patients with SDH-related pheochromocytoma-PGL syndromes. This case illustrates the importance of experienced multidisciplinary team evaluation and management of complex and rare PRG cases. Presentation: Friday, June 16, 2023

Molecular basis of carotid body tumor and associated clinical features in Japan identified by genomic, immunohistochemical, and clinical analyses.

Carotid body tumor (CBT) is classified as a paraganglioma (PGL). Here, we report the genetic background, protein expression pattern, and clinical findings of 30 Japanese CBT cases. Germline pathogenic or likely pathogenic (P/LP) variants of genes encoding succinate dehydrogenase subunits (SDHs) were detected in 15 of 30 cases (50%). The SDHB variants were the most frequently detected, followed by SDHA and SDHD variants. One case with SDHAF2 variant was bilateral CBT, and other two multiple PGL cases were not detected P/LP variants. The three cases with germline variants that could be tested did not have somatic P/LP variants of the same genes. Immunohistochemical analysis showed negative SDHB signals in CBT tissues in five cases with germline P/LP variants of SDHB, SDHD, or SDHA. In addition, SDHB signals in CBT tissues were negative in four of nine cases without germline P/LP variants of SDHs. These findings suggest the involvement of unidentified molecular mechanisms affecting SDHs.

An analysis from the CAPACITY database of outcomes of preoperative embolization before carotid body tumor surgery compared with resection alone

ObjectiveThere is no definitive consensus on the impact of preoperative embolization on carotid body tumor (CBT) treatment. The objective of this study was to compare surgical outcomes of patients who underwent preoperative embolization before CBT resection vs patients who underwent resection alone. MethodsThe CAPACITY registry included 1432 patients with CBT from 11 medical centers in four different countries. The group of patients undergoing CBT resection with preoperative embolization was matched in a 1:6 ratio from a pool of patients from the CAPACITY database, using a generated propensity score with patients who did not underwent preoperative embolization. ResultsA total of 553 patients were included for analysis. Mean patient age was 56.23 ± 12.22 years. Patients were mostly female (n = 469; 84.8%). Bilateral CBT was registered in 60 patients (10.8%). Seventy-nine patients (14.3%) underwent preoperative embolization. Embolized patients had larger CBT sizes than non-embolized patients (33.8 mm vs 18.4 mm; P = .0001). Operative blood loss was lower in the embolized group compared with the non-embolized group (200 mL vs 250 mL; P = .031). Hematomas were more frequent in the non-embolized group (0% vs 2.7%; P = .044). Operative time, rates of stroke, cranial nerve injuries, and death were not statistically significant between groups. ConclusionsEmbolization before CBT resection was associated with significantly lower blood loss and lower neck hematomas than patients who underwent resection alone. Operative time, stroke, cranial nerve injuries, and death were similar between groups.

Bilateral Conjugating Carotid Body Tumor and Associated Jugular Vein Aneurysm.

Carotid body tumors (CBTs) originate from the paraganglionic tissue in the bifurcation of the common carotid artery. Magnetic resonance (MR) imaging is a commonly used diagnostic method in the preoperative diagnosis of these tumors. In this study, we demonstrated an isthmus between the right and left carotid body tumors in a patient with bilateral CBT. The left CBT also was associated with a saccular aneurysm of left external jugular vein.

Perioperative blood pressure and heart rate alterations after carotid body tumor excision: a retrospective study of 108 cases

BackgroundArising from chemoreceptor cells, carotid body tumors (CBTs) are rare neoplasms associated with hemodynamics. Perioperative changes in blood pressure (BP) and heart rate (HR) are not completely understood.MethodsThis retrospective, observational, controlled study included all CBT patients from 2013 to 2018 in Peking Union Medical College Hospital. Perioperative changes in BP/HR within or between unilateral/bilateral/control groups were investigated. Perioperative details across Shamblin types were also assessed.ResultsThis study included 108 patients (116 excised CBTs). The postoperative systolic BP and HR increased in both unilateral (mean difference of systolic BP = 5.9mmHg, 95% CI 3.1 ~ 8.6; mean difference of HR = 3.7 bpm, 95% CI 2.6 ~ 4.9) and bilateral (mean difference of systolic BP = 10.3mmHg, 95% CI 0.6 ~ 19.9; mean difference of HR = 8.4 bpm, 95% CI 0.5 ~ 16.2) CBT patients compared with the preoperative measures. Compared with control group, the postoperative systolic BP increased (difference in the alteration = 6.3mmHg, 95% CI 3.5 ~ 9.0) in unilateral CBT patients; both systolic BP (difference in the alteration = 9.2mmHg, 95% CI 1.1 ~ 17.3) and HR (difference in the alteration = 5.3 bpm, 95% CI 1.0 ~ 9.6) increased in bilateral CBT patients. More CBT patients required extra antihypertensive therapy after surgery than controls (OR = 2.5, 95% CI 1.14 ~ 5.5). Maximum tumor diameter, intraoperative vascular injury, continuous vasoactive agent requirement, total fluid volume, transfusion, estimated blood loss, operation duration, postoperative pathology, overall complications, and intensive care unit/hospital lengths of stay significantly varied among Shamblin types.ConclusionCBT excision may be associated with subtle perioperative hemodynamic changes. Perioperative management of CBT patients necessitates careful assessment, full preparation and close postoperative monitoring.

Physiological and clinical impact in the carotid baroreceptor function following the surgical management of bilateral carotid body tumors.

The bilateral presentation of Carotid Body Tumors (CBT) is rare; the surgical resection of these masses remains the mainstay management due to the malignant potential. We aim to describe, classify, and quantify baroreceptor failure (BRF) after the surgical management of patients with bilateral CBT to better understand the clinical consequences. Retrospective review of patients that underwent bilateral CBT resection to assess the changes in baroreceptor function. We describe the clinical events associated to BRF after surgery, baseline patient's demographics, characteristics, comorbidities. Additionally, clinical and a quantitative evaluation of baroreceptor sensitivity were conducted using the Composite Autonomic Severity Score (CASS). From 1986 to 2020, a total 146 CBT resections were performed in 132 patients in our institution. Tumors were removed bilaterally in staged procedures in seven patients with a mean age of 61years (Standard Deviation 11), six (85%) were females, and there was no family history of paragangliomas. The clinical presentation were palpable masses in 5 (71%), and odynophagia in 2 (29%) cases; malignant histopathology following surgery was found in one case. BRF occurred in one patient after unilateral CBT resection, consisting of bradycardia and a 40s asystole that was not previously associated to BR sensitivity. Three (43%) patients presented BRF in the immediate postoperative period of the contralateral CBT excision, consisting of volatile hypertensive crisis in two cases, and supraventricular tachycardia in one. All the patients developed (100%) chronic baroreceptor sensitivity symptoms consisting in syncope, vertigo and fatigue in 4 (57%), tachycardia in 2 (28%), and orthostatic headache in one (14%). Autonomic testing showed mixed sympathetic and parasympathetic failure in five (71%), severe sympathetic failure in 1 (14%), and parasympathetic dysfunction in one patient (14%). Postoperative autonomic assessment confirmed BRF in all studied patients that underwent staged bilateral CBT resection with mixed, sympathetic, and parasympathetic dysfunction. Further studies are necessary to evaluate the incidence and physiological mechanisms of these sequelae to anticipate possible complications and offer the appropriate perioperative management.

Combined left thoracoscopic and median sternotomy approach to resect aortopulmonary mediastinal paraganglioma following feeding artery embolization: a case report

BackgroundAortopulmonary mediastinal paragangliomas are rare. Complete resection of the tumor is desirable regardless of tumor size in view of the risk of sudden death induced by adjacent organ compression and poor prognosis after partial resection or untreated observation. Due to the hypervascularity of the tumor, the risk of intraoperative bleeding is significant, and cardiopulmonary bypass is often required for complete resection.Case presentationThe patient was diagnosed as having bilateral carotid body tumors and supposedly an aortic body tumor at the age of 43 and eventually underwent resections of bilateral carotid body tumors at the age of 52. The pathology of the carotid body tumors was compatible with paraganglioma on both sides. A familial succinate dehydrogenase subunit D mutation was subsequently identified. Five years later, a contrast-enhanced computed tomography scan showed an enlarged tumor of 45 mm in size in the aortopulmonary mediastinum. Based on the previously known genetic mutation, the tumor was thought to be a paraganglioma. After confirming with an endocrinologist that the aortic body tumor was non-functional, radiologists performed preoperative embolization of the feeding vessels. Subsequently, a surgical team consisting of thoracic and cardiovascular surgeons resected the aortic body tumor using a video-assisted small left thoracotomy approach combined with a median sternotomy approach. The procedure was completed without cardiopulmonary bypass or blood transfusion. The patient was discharged home on postoperative day 9 uneventfully.ConclusionsAfter conduction of preceding interventional embolization of multiple feeding vessels, we employed a video-assisted thoracoscopic surgical approach to dissect the aspects of the tumor adjacent to the esophagus, descending thoracic aorta, and left pulmonary artery, followed by a median sternotomy approach to dissect the other aspects of the tumor adjacent to the ascending aorta, aortic arch, right pulmonary artery, and trachea. There have been no reports on scheduled preoperative embolization of feeding vessels to an aortopulmonary mediastinal paraganglioma. Multidisciplinary approach was effective for complete resection of this challenging rare mediastinal tumor.

Recurrent Gigantic Bilateral Carotid Body Tumors (Paraganglioma): A Rare Case Report

Carotid body tumors (CBTs) affect the chemoreceptors located in the carotid artery bifurcation, and ∼30% will present bilaterally. We report a rare case of bilateral CBTs. The left-side CBT was recurrent after a failed complete excision attempt. Staged surgical excision of both CBTs was planned. Such cases present a real surgical challenge for the surgeon and surgical team. They require meticulous preoperative evaluation, careful operative dissection, prompt decisions, and a multidisciplinary approach for successful outcomes.

Multiparametric ultrasound evaluation of a case of bilateral carotid body tumor

Paragangliomas are a rare form of highly vascularized tumors that originate from paraganglia Baysal (J Med Genet 39: 617–622, 2002). In the head and neck PGL arise primarily in four distinct areas: vagal, middle ear, and larynx and more frequently carotid bifurcation. Imaging evaluations include sonography, color Doppler, US-elastosonography and contrast-enhanced ultrasound (CEUS). Additionally, Computed Tomography, Magnetic Resonance Imaging (MRI) as well as digital subtraction angiography can be performed Stoeckli et al. (Laryngoscope 112: 143–146, 2002). We present herein a case of a rare bilateral carotid body tumor assessed with multiparametric ultrasound evaluation, including CEUS and US-elastography.

Description of a SDHD c.129G>A (p.W43X) Mutation With Variable Presentation in Multiple Family Members

Approximately 40% of paragangliomas and pheochromocytomas are attributed to hereditary mutations. SDHD mutations account for 7% of inherited mutations (PGL1 syndrome), is maternally imprinted and has variable penetrance. SDHD pathogenic variants (PV) have been previously described extensively in Dutch pedigrees, with a varying lifetime risk for tumor development. Here we report a large family (Fig 1) displaying a SDHD c.129G>A (p.W43X) variation in 12 family members, 10 of whom had screening or tumor history available. The presentation and age of diagnosis in family members showed variable penetrance. Age at first diagnosis of a pheochromocytoma/paraganglioma ranged from 10 - 45 years. Family members displayed bilateral pheochromocytomas, bilateral carotid body tumors, and paragangliomas of the head, neck and trunk with variable recurrence rates (none to multiple). No malignant lesions were detected to date. Pheochromocytomas were norepinephrine producing. Paragangliomas ranged from non-functional to dopamine and norepinephrine producing. Compared to previous reports of other SDHD mutations, the SDHD c.129G>A (p.W43X) variation displayed an earlier age at first diagnosis with a highly variable phenotype ranging from one benign, non-secreting paraganglioma to bilateral pheochromocytomas and recurrent parganagliomas along the parasympathetic chain from head to abdomen. This report contributes to the evolving understanding of the phenotypic presentations of various genetic mutations. We propose that expert guidelines that suggest screening family members with the SDHD c.129G>A (p.W43X) variation at the age of 8 for early detection of pheochromocytomas and paragangliomas is beneficial.

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.

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

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

Postoperative secondary aggravation of obstructive sleep apnea-hypopnea syndrome and hypoxemia with bilateral carotid body tumor: A case report

Postoperative secondary aggravation of obstructive sleep apnea-hypopnea syndrome and hypoxemia with bilateral carotid body tumor: A case report

Bilateral Carotid Body Tumor Treated with Primary Radiotherapy and Resected Subsequently: Report of a Case and Review of the Literature

Carotid body tumors (CBT) are rare benign neoplasms of neural crest origin arising from paraganglia cells located at carotid bifurcation. They are usually treated with surgery and occasionally with radiotherapy (RT) as a definitive treatment. We report a case of a carotid body tumor (CBT) in a 45-year old woman who was treated with RT at another institution with intent of diminishing its size and eventually be operated later. This tumor, located on the left side of the neck, appeared 3 years before and was associated with dysphagia and odynophagia. A computed tomography (CT) revealed a lesion of 4.7 cm in size. The patient received 54 Gy of RT. As the tumor persisted clinically, an angio-CT performed one year later showed a left CBT of the same size and a contralateral lesion of 2cm. The surgical resection of this smaller right lesion was performed first and, of the persistent left lesion, one month later. No technical difficulties were found on the resection of the latter tumor and rather decreased peripheral vascularization was present. The histological findings revealed changes due to RT. In an exhaustive review of the literature, there were no findings of any report of surgical resection of a CBT after the primary RT.

MON-249 SDHD Mutation: Nonfunctional Paragangliomas Presenting as Bilateral Carotid Body Tumors with Syncope

SDHD Mutation: Nonfunctional paragangliomas presenting as bilateral carotid body tumors with syncopeBackground:A mutation of the SDHD gene is associated with hereditary paraganglioma-pheochromocytoma (PGL/PCC) syndromes which most commonly originate in the head and neck region, and usually form in the carotid body. Paragangliomas (PGL) can be secretory or non-secretory with about 95% of head and neck PGL being non-secretory. They can rarely present with symptoms due to compression, however, as in this case of a 29 year-old female presenting with syncope.Clinical Case:A 29 year-old female presented for evaluation after syncope. She had a syncopal event and fell down while walking in her home. Syncope was preceded by about 15 minutes of flushing, nausea and palpitations. She reported similar episodes once weekly in the preceding months, which generally lasted an hour. Initial workup included normal vital signs at presentation, normal ECG and echocardiogram, normal TFT, CBC, complete metabolic panel. Subsequent head/neck CT revealed bilateral masses in the carotid bifurcations consistent with carotid body tumors. Further history revealed a family history of bilateral carotid body tumors in her father which had never been evaluated. Plasma and urine metanephrines were normal. She underwent carotid body tumor excision. The left carotid body tumor was successfully excised and pathology revealed a paraganglioma with positive synaptophysin and chromogranin stains. Genetic testing revealed an SDHD (succinate dehydrogenase complex subunit D) gene mutation. Repeat biochemical assessment 4 months later was again negative and patient remained asymptomatic postoperatively.Conclusion:Paragangliomas can be secretory or non-secretory with about 95% of head and neck paragangliomas being non-secretory, as in this case. Symptoms can arise from catecholamine hypersecretion, which generally presents as hypertension, headaches, diaphoresis, flushing, anxiety or palpitations, and can be episodic or sustained, or mass effect. Syncope as a presenting symptom is rare, however, and has not been quantified but only reported in case reports. The exact etiology of syncope in our patient is not clear. Hereditary PGL/PCC syndromes should be suspected in any individual with multiple, recurrent, early-onset (age less than 45 years) or family history of PGL/PCC, as these syndromes are inherited in an autosomal dominant manner.

Case of a Malignant Carotid Body Tumor With Systemic Metastases: The Utility of Multimodal Imaging

Carotid body tumors (CBTs) are rare neoplastic paragangliomas that are typically benign; however, 10% to 15% are malignant with local invasion and, in rare cases, metastases systemically. A 45-year-old woman with a familial history of CBT presented following a syncopal episode. Multimodal imaging confirmed the presence of bilateral CBTs. 68Gallium-DOTATATE Positron Emission Tomography (DOTATATE-PET) scans revealed distant systemic metastases in the liver and vertebra. Surgical intervention was undertaken to excise the less complex right CBT. This report presents a case of malignant CBT with systemic metastases, describing the postintervention multimodal imaging findings with a focus on the duplex ultrasound features.

Surgical Management of Bilateral Carotid Body Tumors

Carotid body tumors (CBTs) are rare neoplasms located in the carotid bifurcation. The majority of these tumors are unilateral; bilateral CBTs represent approximately 5% of all affected patients, and the recommended treatment is to surgically remove them in staged-planned surgeries. We describe the experience, outcomes, and the surgical management of bilateral CBTs in our institution. A retrospective review of CBTs patients was completed; patient demographics, comorbidities, lesion location, anatomic characteristics, surgical techniques, complications, reinterventions, and other factors that may influence outcomes were evaluated. A total of 109 patients with CBTs were treated surgically; of these, 8 had bilateral CBTs (7%); the mean age was 56years, and 7 (87%) were females. Thirteen surgical resections were performed, and in 2 of the cases, the pathology report was malignant (15%). Five were classified as Shamblin I (31%), 5 as Shamblin II (31%), and remaining 6 as Shamblin III (38%). The mean time between the first and second procedure was of 10.7months. Complications included one case of neck hematoma requiring evacuation and postoperative neurologic complications occurred in three patients (one patient with facial and two with vocal cord palsies). None of the studied individuals had a family history of CBT, and all of them lived in altitude areas higher than 2000meters above mean sea level (mamsl). The mean tumor size was 3.55cm and 2.75cm for right and left CBTs, respectively. A better understanding of the clinical characteristics of patients with bilateral CBTs may lead to a more standardized and optimal management with fewer complications and a better quality of life afterward.

SDHx gene detection and clinical Phenotypic analysis of multiple paraganglioma in the head and neck

The goal of this study was to detect and explore the mechanisms of the succinate dehydrogenase (SDH) complex subunit-related gene mutations in cases of multiple paraganglioma (PGL) in the head and neck. In Beijing Tongren Hospital (Capital Medical University, Beijing, People's Republic of China) between January 2013 and February 2017, 23 cases of head and neck multiple PGL were evaluated by genetic sequencing. From these cases, four hereditary families and 10 cases with sporadic occurrences were found. Gene mutations, including SDHD, SDHB, SDHC, SDHAF2, VHL and RET in germ cells and somatic cells, were detected by gene capture and high throughput sequencing. In family 1, 12 instances of SDHD gene mutation were detected, eight of which manifested as bilateral carotid body tumor (CBT) with one bilateral malignant CBT. In family 2, three cases of SDHD mutation were found with one case of bilateral CBT and two cases of unilateral CBT. In family 3, two cases of SDHD gene mutation were found, both characterized by vagus PGL and pheochromocytoma. Of the 10 patients with sporadic manifestations, five cases of SDHD gene mutation and one case of RET gene mutation were detected. Two novel gene mutations, c.387_393del7 mutation of SDHD gene and c.3247A>G mutation of RET gene, were also detected. In patients with multiple PGL in the head and neck, these are accompanied by a genetic mutation of the germ cell. In this case study, this mutation was most commonly a mutation of the SDHD gene. 4 Laryngoscope, 129:E67-E71, 2019.

DON’T FORGET TO BREATHE: A CASE OF HYPOXEMIA AFTER CAROTID BODY RESECTION

SESSION TITLE: Pulmonary Physiology SESSION TYPE: Fellow Case Report Posters PRESENTED ON: 10/09/2018 01:15 PM - 02:15 PM INTRODUCTION: Carotid body tumors (CBTs) are paragangliomas, slow-growing neuroendocrine tumors that secrete catecholamines. Management involves surgical resection or radiation. Although chronic hypoxia has been identified after resection of these tumors, the effects of altitude on oxygenation in these patients has not been well-described. We present a case of chronic hypoxia in a patient after bilateral CBT resection. CASE PRESENTATION: A 72 year-old male with a personal and family history of bilateral CBTs presented for evaluation of hypoxia. He underwent resection of these tumors one year prior to presentation. Final tissue exam identified benign carotid body paragangliomas. He had a significant history of tobacco use but had quit 5 years prior. Given his new hypoxia, he underwent evaluation for COPD. Review of systems was notable for dyspnea with heavy exertion but he was otherwise without respiratory complaints. He lived at 1200m above sea level without significant dyspnea, but frequently traveled to 2500m above sea level where his dyspnea would worsen. On exam his baseline SpO2 was 90-91%, but increased quickly to 97-98% with frequent deep breaths. Due to concern for COPD, pulmonary function testing (PFT), plethysmography and DLCO were obtained and all normal. 6MWT was significant for desaturations that improved with 2-3L/min of supplemental O2. ABG showed minimal hypoventilation with a PaCO2 42mm Hg at rest. Overnight oximetry showed mild sustained hypoxemia. CT chest, PET and a V/Q scan were obtained and were all unremarkable. The patient was started on 2-3L/min of supplemental O2 with ambulation and sleep. At one year follow-up he reported control of his dyspnea even at high altitudes. DISCUSSION: The effects of ventilatory control in patients after bilateral carotid-body resection has been previously described. It is theorized that the carotid bodies are responsible for the hyperpnea that results from hypoxia; the aortic chemoreceptors to a much lesser extent. Brainstem respiratory centers receive afferent impulses from the carotid bodies during hypoxia and hypercapnia to control ventilation by increasing MV. In those who have undergone bilateral carotid body resection, there is minimal to no change in MV during hypoxia. At altitudes higher than 2000m the atmospheric O2 pressure decreases causing chronic hypoxia. This case demonstrates the effects of this reduced atmospheric O2 pressure in a patient that has undergone a bilateral carotid body resection. CONCLUSIONS: Providers should be aware that in patients who have undergone carotid body resection, regulatory control of ventilation is impaired, resulting in diminished increase in MV response to hypoxia. At higher altitudes, this becomes clinically significant due to the reduced atmospheric O2 pressure inspired. Patients with hypoxia after bilateral carotid body resections should be advised to use supplementary O2, especially at high altitudes. Reference #1: Erickson et al. “Benign Paragangliomas.” J Clin Endocrinol Metab. 2001 Nov; 86 (11): 5210-5216. Reference #2: Lugliani et al. “Effect of bilateral carotid-body resection on ventilatory control at rest and during exercise in man,” The New England Journal of Medicine. 1971; 285 (20):1105–1111. Reference #3: Rodríguez-Cuevas et al. "Carotid body tumors in inhabitants of altitudes higher than 2000 meters above sea level.” Head & Neck. 1998; 20:374-378. DISCLOSURES: No relevant relationships by David Dorsey, source=Web Response No relevant relationships by Brian Foster, source=Web Response