Carotid body tumor: characteristics and surgical outcome.

BACKGROUND: Carotid body tumors are uncommon neuroendocrine growths near the carotid bifurcation. While some advocate preoperative embolization to minimize bleeding, others avoid it due to complications. This study shares the experience of a single center in managing patients with carotid body tumors without practicing preoperative embolization. METHODS: This was a cross-sectional study of patients with carotid body tumors managed between 2020 and 2024. Data were collected from the hospital's registry. When necessary, routine blood tests, neck ultrasonography, and computed tomography scans were conducted. The tumors were categorized according to Shamblin's classification. The average duration of follow-up was 20 months. RESULTS: The study involved 25 patients, 22 (88%) females and 3 (12%) males. Their ages ranged from 27 to 85 years old. Twenty (80%) cases presented with neck swelling, and six (24%) had a positive medical history. Tumors were mainly on the right side (52%), with 20 (80%) showing ill-defined neck masses. Tumor sizes ranged from 1.5 to 7 cm, with Shamblin type II tumors being discovered in the majority of cases (72%). Types of tumors were significantly associated with the tumor size (p-value < 0.05). Blood transfusion was required in five cases (20%), three from type III and two from type II, with none from type I (p-value = 0.001). Temporary neurological deficits occurred in 3 cases (12%). No functional impairment or mortality was recorded. CONCLUSIONS: Carotid body tumors are rare tumors with an unknown etiology. Operation without practicing preoperative embolization may be feasible with an acceptable outcome.

Computed tomographic findings in canine and feline heart base tumors (25 cases).

Tumors located at the heart base are rare in dogs and cats and aortic body tumors (chemodectoma/paraganglioma), hemangiosarcoma, ectopic thyroid carcinoma, lymphoma, and other uncommon neoplasia can be found at that location. The objective of this retrospective case series was to describe the CT characteristics of canine and feline heart base tumors. CT studies of 21 dogs and four cats with histologically or cytologically confirmed heart base tumors were reviewed for size, location, shape, margination, contrast enhancement, adjacent neovascularization, invasion, mass effect, cavitary effusions, and metastasis. Neuroendocrine tumors (15 aortic body tumors, three ectopic thyroid carcinoma, and three nonspecific neuroendocrine) were more commonly observed than hemangiosarcoma (4) and were frequently located between the cranial vena cava and aortic arch (12/21; 57%) and or dorsal to the pulmonary trunk bifurcation/pulmonary arteries (10/21; 48%). Hemangiosarcoma was more commonly found cranioventral to the aortic arch and cranial to the right auricular appendage (3/4; 75%). Mediastinal and peritumoral neovascularization was associated with 16/21 (76%) neuroendocrine tumors but none of the hemangiosarcoma. Median postcontrast attenuation in Hounsfield units (HU) was higher in neuroendocrine (110 HU) than in hemangiosarcoma (51 HU). Pericardial effusion was frequently observed with hemangiosarcoma (3/4; 75%) and infrequently in neuroendocrine (3/21; 14%). In four cases (all neuroendocrine), concurrent cranial mediastinal masses were present. CT provides useful information regarding the characteristics of heart base tumors, indicating differences between the appearance of neuroendocrine tumors and hemangiosarcoma. However, no differences were found between aortic body tumors and ectopic thyroid carcinoma.

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.

Case report: Malignant chemodectoma with hepatic metastasis in a cat.

A 10-year-old, male-neutered, domestic short-hair cat was examined at the Veterinary Health Center Emergency Service at Kansas State University for a one-day history of dyspnea. Prior to thoracocentesis, sedation was provided. The cat stopped breathing after sedation and went into cardiac arrest. Cardiopulmonary resuscitation (CPR) was unsuccessful. At necropsy, there was severe pleural effusion and bilateral pulmonary atelectasis. The myocardium of the atria and ventricles, and tunica adventitia of coronary vessels, pulmonary artery, and aorta, had pale, firm, multinodular masses ranging from 0.3 to 0.5 cm in diameter. Multiple nodules were also present in the liver. Multifocally expanding the epicardial fat and compressing the underlying epicardium, infiltrating, and expanding the myocardium, and expanding the walls of major vessels, there was a multinodular, unencapsulated, densely cellular neoplasm composed of polygonal epithelial cells arranged in nests and packets and supported by a fine fibrovascular stroma. The nodules in the liver had similar histologic features. In this case, neoplastic cells at the primary and metastatic sites were intensely immunoreactive to synaptophysin, variably reactive to chromogranin A, and negative for neuron specific enolase, cytokeratin, vimentin, thyroglobulin, and smooth muscle actin. The gross, histologic, and immunohistochemical findings support the diagnosis of chemodectoma, with metastases to the liver. Synaptophysin and chromogranin A were the most useful immunohistochemical markers to diagnose malignant chemodectoma in this cat.

Malignant carotid body tumor: a report of two cases.

Carotid body tumors (CBT) are neoplasms that originate from chemoreceptors of the carotid body. They are neuroendocrine tumors that are usually benign but may have malignant potential. Malignancy is diagnosed with evidence of lymph node metastasis, distant metastasis, or disease recurrence. Multiple imaging modalities are used to diagnose CBTs and the treatment of choice is surgical excision. Radiotherapy is used for unresectable tumors. In this case, series we describe two cases of malignant paragangliomas that were diagnosed and operated on at a tertiary hospital in Kuwait, by the vascular team. Malignant CBTs are rare, documentation of the cases encountered and the subsequent management and outcome is important to give us a better understanding of the disease. Case presentation: Case one- A 23-year-old woman presented with a right-sided neck mass. History, physical examination, and appropriate imaging suggested malignant paraganglioma with evidence of lymph node, vertebral, and lung metastases. Surgical excision of the tumor and regional lymph nodes was done. Histopathological assessment of the retrieved specimens confirmed the diagnosis. Case two - A 29-year-old woman presented with a left submandibular swelling. She was appropriately investigated, and the diagnosis of a malignant carotid body tumor was made with evidence of lymph node metastasis. Surgical resection of the tumor with clear margins was done and histopathological analysis of the resected specimen confirmed the diagnosis. Clinical discussion: CBT's are the most common tumors of the head and neck. Most are nonfunctioning, slow growing, and benign. They typically present in the fifth decade of life but can occur at a younger age in individuals who carry certain genetic mutations. Both cases of malignant CBT's that we encountered occurred in young women. Furthermore, the 4-year and 7-year history in case number one and two, respectively, supports the fact that CBTs are slow growing tumors. In our case series, the tumors were surgically resected. Both cases were discussed in multidisciplinary meetings and were referred for hereditary testing and radiation oncology for further management. Conclusion: Malignant carotid body tumors are rare. Prompt diagnosis and treatment is important to improve patient outcomes.

A Rare Case of Diffuse Bilateral Minute Pulmonary Meningothelial-like Nodules Increasing over the Short Term and Resembling Metastatic Lung Cancer.

A 54-year-old woman was referred to our hospital because computed tomography (CT) revealed multiple lung nodules during a health checkup. The nodules were up to 5 mm in diameter and randomly distributed in both lungs, appearing ring-shaped. No clinical symptoms were present. However, the nodes proliferated, and multiple lung metastases could not be ruled out, so a biopsy was performed to establish a diagnosis. She was diagnosed with minute pulmonary meningothelial-like nodules (MPMNs), and her condition had not deteriorated at the latest follow-up. Although rare, MPMNs can proliferate for a short time, but a biopsy to exclude malignant causes is essential.

Toceranib phosphate resolves right heart obstruction secondary to a heart base neoplasm in a dog.

An eight-year-old castrated male, 45 kg labrador retriever presented for evaluation of a two-week history of cough and tachypnoea. Echocardiography revealed an approximately 10 cm heart base mass, which extended to the right atrioventricular junction, causing compression of both the right atrium and ventricle resulting in right-sided congestive heart failure (abdominal effusion). Cytology of the mass was consistent with a neuroendocrine carcinoma. Given the location and description, a chemodectoma or ectopic thyroid carcinoma was suspected. The patient was treated with toceranib phosphate and famotidine. At the follow-up appointment four weeks later, the right heart compression had resolved due to a clinically significant reduction in the size of the mass. The patient was prescribed furosemide and enalapril to treat right-sided congestive heart failure. When considering treatment options for haemodynamically significant heart base masses, treatment with toceranib phosphate may result in rapid clinical benefit.

Caval chemodectoma in a cat.

Case summary: An 11-year-old male neutered domestic shorthair cat was presented with a 4-week history of an intermittent cough and dyspnoea. A pleural effusion was identified, which was confirmed as chyle. Echocardiography and CT revealed a 16 mm mass cranial to the heart, which was invading the cranial vena cava. Because of the location of the mass, it was assumed that chylothorax had developed as a result of direct disruption of the thoracic duct by the tumour or secondarily to central venous hypertension. An exploratory thoracotomy was performed, and the mass, which originated within the wall of the cranial vena cava, was excised with narrow gross margins. Histopathology and immunohistochemistry were consistent with a chemodectoma with residual tumour cells at the surgical margin. Given the residual microscopic disease, adjuvant treatment with toceranib phosphate was initiated. The cat remained well for the duration of treatment and was euthanased 31 months after diagnosis when CT identified recurrent pleural effusion, a heart base mass with cranial vena cava and azygos vein invasion. Relevance and novel information: Chemodectomas are rare in cats, with only 13 cases reported in the literature to date, and all were located in either the aortic or carotid body. The reported survival with partial resection and/or subtotal pericardiectomy was 13-19 months. Treatment of feline chemodectomas with toceranib phosphate has not been previously reported. To our knowledge, this is the first description of the surgical management of a feline vena cava chemodectoma, combined with adjuvant toceranib phosphate, resulting in a prolonged survival.

[Modern conceptions on neck paragangliomas]. / Paragangliomy shei.

Neck paragangliomas are orphan diseases with incidence 1:30 000-1:100 000. Life expectancy is poor in patients with distant metastasis (5-year overall survival 11.8%), whereas 5-year overall survival in patients with regional metastasis is 76.8-82.4%. Meanwhile, there is still no any reliable tool for prediction of malignant potential of paraganglioma. Above-mentioned data indicate an importance of early diagnosis and timely treatment of neck paragangliomas. Total resection of tumor in ablastic conditions is a gold standard of treatment. However, surgery is associated with a high risk of neurovascular complications and requires multidisciplinary approach. Nevertheless, new knowledge dedicated to different aspects of pathogenesis of neck paraganglioma, diagnosis and treatment arise every year. This review is devoted to modern data on neck paragangliomas.

A Carotid Body Tumour Mimicking Richter's Transformation of Chronic Lymphocytic Leukaemia.

Carotid body tumours (CBT), also called carotid paragangliomas, are highly vascular glomus tumours that originate from paraganglionic cells of the carotid body. They are frequently asymptomatic, insidious, and non-secretory in nature. They typically present as a large, non-tender, pulsatile neck mass. Careful evaluation of a neck mass, with the aid of imaging, is necessary to avoid a misdiagnosis. We herein describe a case of a 77-year-old gentleman with a background of chronic B-cell lymphocytic leukaemia, who was found to have a rapidly enlarging, asymptomatic neck mass along with multiple enlarged lymph nodes in the axillae. Given his past medical history, the preliminary diagnosis was Richter's transformation. However, the characteristic splaying of the internal and external carotid arteries on imaging prompted us to consider the diagnosis of a CBT. The patient was referred to vascular surgeons for surgical excision of the tumour. Histology confirmed that the neck mass was indeed a CBT. Ultrasound-guided core biopsy of the axillary lymph nodes revealed a concomitant Hodgkin-like Richter's transformation. This case exemplifies how we were able to differentiate between a CBT and nodal mass with the aid of various imaging modalities. An accurate diagnosis allows clinicians to deliver the appropriate management; the treatment for CBT is surgical excision, whereas chemotherapy is the first-line treatment for Richter's transformation.

Giant carotid chemodectoma treated with a combination of surgery and CyberKnife radiotherapy: a case report and review of the literature.

BACKGROUND: Paragangliomas are rare vascular neuroendocrine tumors that develop in the extra-adrenal paraganglion tissue. They occur most commonly at the carotid bifurcation, where they are known as carotid body tumors. Most paragangliomas are benign, locally aggressive, infiltrative tumors. Approximately 10% of patients with paragangliomas develop distant metastases, 10% present with multiple or bilateral tumors (mostly carotid body tumors), and 10% have a family history of paragangliomas. The malignant transformation of carotid body tumors has been reported in 6% of cases. CASE PRESENTATION: We present the case of a 64 year-old Caucasian woman with a gigantic glomic tumor mass in the neck. Twenty years before the consultation, the patient had undergone an unsuccessful attempt to remove the mass. Over the last 3 years, the patient had felt enlargement of the mass at an increased rate, almost doubling the prior size. Angio magnetic resonance imaging showed a 9 cm paratracheal mass on the left cervical side that laterally displaced the sternocleidomastoid muscle and 2 c m of the trachea. Due to the change in the tumor behavior, the maxillofacial team at Ruber International Hospital decided to remove the tumor surgically after embolization. During the surgery the tumor was gently dissected from the carotid an removed from the carotid bifurcation uneventfully. Two small nodes adhering tightly to the internal carotid adventitia and the posterior torn hole were left in place to avoid any potentially life-threatening complications. The final biopsy confirmed the initial diagnosis of carotid body paraganglioma and showed a Ki-67 expression of 19%. Due to the aggressive growth behavior and high Ki-67 expression of the tumor, the patient was referred to the CyberKnife Unit of Ruber International Hospital for treatment of the remaining nodes. CONCLUSIONS: The management of cervical paragangliomas is difficult and remains a challenge. Although the likelihood of tumor control is high with surgical or radiotherapeutic treatments, we currently lack consensus regarding the best treatment option. Nevertheless, in selected complex cases, such as the case we present, the combination of surgery and radiosurgery may allow complete local tumor control with minimal morbidity.

Ultrasound-Guided Radiofrequency Ablation of Chemodectomas in Five Dogs.

Chemodectomas are low prevalence tumors with complex clinical management. Many present as an incidental finding however, in other dogs, they produce pericardial effusion and/or compression, leading to the appearance of severe clinical signs. There are currently several approaches: surgery, radiotherapy, stent placement and chemotherapy. This is the first description of percutaneous echo-guided radiofrequency ablation of aortic body tumors. This minimally invasive treatment is based on high frequency alternating electrical currents from an electrode that produces ionic agitation and generates frictional heat, causing coagulation necrosis. Five dogs with an echocardiographic and cytological diagnosis of chemodectoma underwent percutaneous echo-guided radiofrequency ablation. At the time of presentation, all the dogs showed clinical signs, such as ascites and/or collapse. There were no complications either during the procedure or in the following 24 hours. Rapid clinical improvement associated with a reduction in size and change in sonographic appearance of the mass were achieved with no complications. Six months follow-up was carried out in all dogs. A second percutaneous echo-guided RFA was performed eight months after the first procedure in one dog. Based on our experience, radiofrequency ablation seems to be a feasible and safe technique, making it a potential alternative therapeutic approach in the clinical management of aortic body tumors leading to severe clinical compromise.

Glomus carotídeo en la infancia. Presentación de un caso clínico / Carotid glomus in childhood: presentation of a clinical case

Introducción: El glomus carotídeo es un paraganglioma extraadre-nal, excepcional en la infancia, cuyo origen es el cuerpo carotídeo. Soloel 3% de los paragangliomas se presentan en cabeza y cuello. Existeun 10% de formas familiares asociadas a mutaciones en el gen de lasuccinato deshidrogenasa (SDH), porcentaje que es mayor en la infancia.Son tumores benignos en un 95% de los pacientes, pero pueden afectarpor extensión a ambas carótidas. Su tratamiento es quirúrgico con o sinembolización previa. Las metástasis son raras y están asociadas a losescasos casos de malignidad. Caso clínico: Paciente de 8 años de edad con masa cervical de 4meses de evolución, serologías normales. Como antecedente destacauna tía sometida a cirugía cervical. Ecográficamente se objetiva masahipoecoica muy vascularizada en probable relación con glomus ca-rotídeo. Se decide resección quirúrgica sin embolización que resultacompleta y sin incidencias. Estudio genético positivo para la mutaciónen el gen de la SDH. Conclusión: El glomus carotídeo en la infancia ha de ser tenido encuenta como diagnóstico diferencial en masas cervicales. El tratamientoquirúrgico sin embolización previa es una opción terapéutica segura encasos seleccionados.(AU)

Introduction: Carotid glomus is an exceptional extra-adrenal para-ganglioma in childhood originating at the carotid body. Only 3% ofparagangliomas occur in the head and the neck. Familial forms, associ-ated with Succinate Dehydrogenase (SDH) gene mutations, account for10% of cases, the proportion being higher in childhood. They are benignin 95% of patients, but they can extend to both carotids. Treatment issurgical with or without previous embolization. Metastasis is rare andassociated with malignant cases, which are limited. Clinical case. 8-year-old patient with a cervical mass originating4 months ago and normal serum levels. Regarding family history, shehad an aunt who underwent cervical surgery. Ultrasound examinationdemonstrated a greatly vascularized hypoechoic mass most likely relatedto carotid glomus. Full surgical resection without embolization wasdecided upon, which proved uneventful. The genetic study was positivefor SDH gene mutation.Conclusion: Carotid glomus in childhood should be considered as adifferential diagnosis in cervical masses. Surgical treatment without pre-vious embolization represents a safe therapeutic option in selected cases.(AU)

Carotid glomus in childhood: presentation of a clinical case. / Glomus carotídeo en la infancia. Presentación de un caso clínico.

INTRODUCTION: Carotid glomus is an exceptional extra-adrenal paraganglioma in childhood originating at the carotid body. Only 3% of paragangliomas occur in the head and the neck. Familial forms, associated with Succinate Dehydrogenase (SDH) gene mutations, account for 10% of cases, the proportion being higher in childhood. They are benign in 95% of patients, but they can extend to both carotids. Treatment is surgical with or without previous embolization. Metastasis is rare and associated with malignant cases, which are limited. CLINICAL CASE: 8-year-old patient with a cervical mass originating 4 months ago and normal serum levels. Regarding family history, she had an aunt who underwent cervical surgery. Ultrasound examination demonstrated a greatly vascularized hypoechoic mass most likely related to carotid glomus. Full surgical resection without embolization was decided upon, which proved uneventful. The genetic study was positive for SDH gene mutation. CONCLUSION: Carotid glomus in childhood should be considered as a differential diagnosis in cervical masses. Surgical treatment without previous embolization represents a safe therapeutic option in selected cases.

INTRODUCCION: El glomus carotídeo es un paraganglioma extraadrenal, excepcional en la infancia, cuyo origen es el cuerpo carotídeo. Solo el 3% de los paragangliomas se presentan en cabeza y cuello. Existe un 10% de formas familiares asociadas a mutaciones en el gen de la succinato deshidrogenasa (SDH), porcentaje que es mayor en la infancia. Son tumores benignos en un 95% de los pacientes, pero pueden afectar por extensión a ambas carótidas. Su tratamiento es quirúrgico con o sin embolización previa. Las metástasis son raras y están asociadas a los escasos casos de malignidad. CASO CLINICO: Paciente de 8 años de edad con masa cervical de 4 meses de evolución, serologías normales. Como antecedente destaca una tía sometida a cirugía cervical. Ecográficamente se objetiva masa hipoecoica muy vascularizada en probable relación con glomus carotídeo. Se decide resección quirúrgica sin embolización que resulta completa y sin incidencias. Estudio genético positivo para la mutación en el gen de la SDH. CONCLUSION: El glomus carotídeo en la infancia ha de ser tenido en cuenta como diagnóstico diferencial en masas cervicales. El tratamiento quirúrgico sin embolización previa es una opción terapéutica segura en casos seleccionados.

Superselective carotid body tumor embolization with platinum-based coils.

Resection of Shamblin II and III carotid body tumors can be challenging owing to the potential for significant blood loss. Prophylactic use of liquid embolic agents poses a risk of inflammatory reactions and nontarget embolization. On the other hand, coil embolization has traditionally been limited to cases involving external carotid artery sacrifice. Herein we demonstrate that superselective targeting of tumor-feeding vessels using platinum based, fully detachable packing coils is effective at sustained devascularization of Shamblin II and III carotid body tumors without subsequent inflammation, allowing for a longer interval between embolization and tumor resection, and potentially reducing blood loss without need for ligation or reconstruction of the internal or external carotid artery.

Choroidal neuroendocrine neoplasia in a dog.

OBJECTIVE: To report onset and progression of clinical signs of a neuroendocrine neoplasm (NEN) presumed metastatic to the choroid in a dog. ANIMALS STUDIED: A 7.5-year-old female spayed German shepherd dog mix referred for advanced imaging and evaluation of a subretinal mass in the right eye. PROCEDURES: Procedures performed included general physical and ophthalmic examinations; ocular, orbital, and abdominal ultrasonography; thoracic radiographs; cranial magnetic resonance imaging; serologic testing for infectious agents; analysis of hematologic as well as serum and urine biochemical parameters; echocardiography; electrocardiography; cytologic assessment of lymph nodes; and histopathology and immunohistochemistry of the enucleated globe. RESULTS: Examination and imaging identified a pigmented mass within and expanding the superior choroid. Following enucleation, a choroidal NEN with tumor emboli in scleral blood vessels was diagnosed by histopathologic assessment and confirmed by immunohistochemical labelling. Despite extensive and repeated diagnostic testing over many months, a putative primary site was not identified until 19 months after the initial ocular signs were noted. At that time, a heart-base mass and congestive heart failure were highly suggestive of a chemodectoma. CONCLUSION: This comprehensive report of a NEN presumed metastatic to the choroid in a dog suggests that ocular disease can be a very early and solitary sign of NEN in the dog.

Long-term outcomes with conventional fractionated and stereotactic radiotherapy for suspected heart-base tumours in dogs.

Published radiotherapy results for suspected heart-based tumours in dogs are limited. In this retrospective longitudinal study (3/2014-2019), eight dogs with either clinical signs attributable to a heart-base mass (6), or asymptomatic with a progressively larger mass on echocardiogram (2), received conventional fractionated radiotherapy (CFRT) or stereotactic body radiotherapy (SBRT). Clinical findings in symptomatic cases included one or more of the following: retching/coughing (4), exercise intolerance (2), collapse (1), pericardial effusion (2), rare ventricular premature contractions (2), abdominal effusion (1), or respiratory distress due to chylothorax (1). CFRT cases received 50 Gray (Gy) in 20 fractions and SBRT cases received 30 Gy in 5 or 24 Gy in three fractions. Two dogs received chemotherapy post-radiation. At analysis, 7/8 dogs were deceased and one was alive 684 days post-treatment. The estimated median overall survival (MOS) from first treatment was 785 days (95% CI 114-868 days, [range 114-1492 days]). Five dogs received CFRT (MOS 817 days; (95% CI 155 days-not reached [range 155-1492 days])). Three dogs received SBRT with one alive at analysis (MOS 414 days, (95% CI, 114 days-not reached [range 114-414 days])). No statistically significant difference was found between survival for CFRT and SBRT. Of the symptomatic patients, 5/6 showed improvement. Mass size reduced in 4/5 cases receiving follow-up ultrasounds. Possible complications included asymptomatic radiation pneumonitis (4), atrial tachycardia/premature beats (4) and pericardial effusion with heart failure coincident with tumour progression (1). This study provides preliminary evidence that radiotherapy may impact clinically relevant or progressively enlarging heart-base masses.

A retrospective analysis of stereotactic body radiation therapy for canine heart base tumors: 26 cases.

INTRODUCTION: This study retrospectively evaluated outcomes and adverse radiation effects (AREs) associated with stereotactic body radiation therapy (SBRT) for canine heart base tumors (HBTs). A secondary aim was to identify any demographic or echocardiographic factors that might determine which dogs would most benefit from SBRT. ANIMALS: Twenty-six dogs that received SBRT for an imaging-based diagnosis of a HBT were evaluated. METHODS: Twenty-three dogs were treated with three fractions of 10 Gy delivered daily or every other day. The remaining 3 dogs received variable protocols of one to five fractions. Demographic, echocardiographic, and radiographic information, AREs, and treatment responses were collected. Correlations of these data with survival time were evaluated. RESULTS: The median overall survival time was 404 days (95% confidence interval: 239-554 days). The majority of dogs experienced a partial response (25%) or stable disease (60%) for a median duration of 333 days (95% confidence interval: 94-526 days). Three dogs had progressive disease within six months of SBRT. Radiographic pneumonitis was identified in 7 of 23 dogs, and clinical pneumonitis was identified in 4 dogs. No other AREs were noted. The rate of distant metastasis was 13%. On multivariate analysis, it was found that vena caval obstruction, supraventricular and ventricular arrhythmias, clinical signs, and enlarged locoregional lymph nodes at presentation were negatively associated with survival time. CONCLUSIONS: Stereotactic body radiation therapy was delivered with a low rate and degree of normal tissue complications. Asymptomatic dogs with confirmed, progressive growth of a HBT may most likely benefit from SBRT.

Surgical Excision of Carotid Body Tumor at an Early Stage Has Best Outcome: Result of 22 Cases along with Literature Review.

Objective: The objective of this study is to share our experience of early surgical excision of highly vascular carotid body tumor (CBT) and to correlate it with current literature. Materials and Methods: Data of all consecutive patients diagnosed with CBT from September 2011 to September 2018, who underwent surgical excision, was analyzed. Results: Of the 22 cases with mean age of 42±standard deviation (SD) 6 years and female to male ratio of 1.2 : 1, 68.1% (n=15) of the tumors were on the right side. There were 13.6% (n=3) Shamblin I, 77.2% (n=17) Shamblin II, and 9% (n=2) Shamblin III tumors. Complete excision without vascular reconstruction was achieved in 63.6% (n=14), while patch plasty with Dacron graft was noted in 29.4% (n=5) and interposition Dacron grafting 13.6% (n=3). Peroperative vascular shunt was deployed in 13.6% (n=3) of cases. Transient neuropraxia of the hypoglossal nerve was noted in 13.6% (n=3) of cases, while permanent drooping of the lower lip was noted in 4.5% (n=1). There was no ischemic stroke. The mortality rate was zero, and no recurrence was recorded in mean follow-up of 24±SD 3 months. Conclusion: Complete surgical excision of CBT at an early stage, regardless of size, is associated with the best outcome.

Carotid Body Tumor Microenvironment.

Carotid body tumors (CBTs) are rare paragangliomas, comprising 0.5% of all head and neck tumors, and 65% of head and neck paragangliomas. A majority of CBTs occur sporadically, while 15% are familial or hyperplastic in the setting of chronic hypoxia. They usually present as unilateral, well-circumscribed rubbery masses, arising at the level of the carotid bifurcation. A majority of CBTs are painless and therefore may evade diagnosis for months to years. Symptomatic lesions occur due to progressive cranial nerve IX, X, or XII dysfunction, manifesting as hoarseness, dysphagia, vertigo, coughing, or odynophagia. Other local symptoms include neck discomfort, pulsatile tinnitus, hearing loss, or carotid sinus syndrome. Appropriate workup includes a thorough physical exam followed by radiographic imaging, vascular studies, and biochemical workup with 24 h urinary catecholamine or metanephrine analysis. The management of these tumors, which involves standalone surgical resection or following embolization for larger and more vascular tumors, will also be discussed.