Genetic testing in head and neck paraganglioma: who, what, and why?

The Radiological Assessment of Carotid Space Lesions: A Case Series

Carotid space lesions present diagnostic challenges due to their diverse etiology and varied clinical manifestations. This article critically reviews the anatomy of the carotid space and highlights the spectrum of pathologies within this complex region, illustrated by three case studies. The cases were examined with ultrasonography (USG), computed tomography (CT), and magnetic resonance imaging (MRI). Schwannomas appeared heterogeneously hypodense on plain CT and partially hyperdense on contrast-enhanced CT (CECT), with displacement of adjacent vessels. Vagal-origin schwannomas caused the anteromedial displacement of the internal carotid artery. Paragangliomas were typically homogeneously hyperdense on CECT, with lateral displacement of the internal carotid artery when of carotid body origin. The management of carotid space lesions depends on the resectability of the tumors; unresectable tumors are managed with chemotherapy. This overview enhances clinical understanding and diagnostic accuracy, facilitating improved patient outcomes in managing carotid space lesions.

Reduced Risk of Corporal Tumors in Patients With Head and Neck Paragangliomas With p.Pro81Leu Mutations

OBJECTIVE

Patients with head and neck paragangliomas who are positive for the SDHD p.Pro81Leu (P81L) mutation are thought to have a distinct phenotype from other SDHx mutations, but few studies have focused on this mutation. The objective of this study was to determine the hazard of developing a second primary, metastatic, or recurrent paraganglioma in SDHx patients with or without P81L.

STUDY DESIGN

Retrospective chart review of 60 patients with head and neck paragangliomas and genetic testing, followed for a median of 9 years.

SETTING

Single academic medical center.

METHODS

Univariable Cox proportional hazards regression evaluated second primary and recurrent paragangliomas in patients with SDHD P81L, SDHx non-P81L, and nonhereditary paraganglioma.

RESULTS

This series comprised 31 patients without SDHx, 14 with SDHD P81L, and 15 with other SDHx mutations. At a median 9 years of follow-up, corporal (not head and neck) second primary paragangliomas occurred in 31% of patients with SDHx non-P81L mutations, compared with 0% and 4% of patients with SDHD P81L and without SDHx mutations, respectively. Second corporal paragangliomas were more likely in patients with SDHx non-P81L mutations than in those without a mutation (hazard ratio = 5.461, 95% confidence interval: 0.596-50.030, p = .13).

CONCLUSION

This is the first study to report a lower likelihood of corporal tumors for patients with head and neck paragangliomas with SDH mutations positive for P81L. Larger studies are needed to determine if head and neck paraganglioma patients with P81L qualify for less intensive imaging surveillance to screen for second primary paragangliomas outside the head and neck.

Can Superoxide Anions Predict the Malignant Potential of Carotid body Tumor? - A Pilot Study

Currently, there is no consensus on estimating the malignant potential of Carotid Body Tumor (CBT) and the only way to predict a metastatic CBT is through DOTANOC Positron Emission Tomography (PET) scan. There is a well-established correlation between CBT and superoxide anions inside tumor cells. The purpose of this pilot study was to measure superoxide anions inside CBT cells and find if these can be used as marker to predict malignant potential of CBT. The results were also co-related with findings of DOTANOC PET scan retrospectively. The CBT tissue from 10 patients was stained using a fluorogenic dye and superoxide anions were measured by analysis of fluorescent image. The patients were divided into two groups - First group with four patients having potentially malignant CBT based upon clinico-surgical characteristics and second group with the rest of the six patients. It was seen that the superoxide anions were highest in the first group which included patients with metastatic carotid body tumor, patients with multiple paragangliomas and patient with positive family history (p = 0.011). The same patients also had metastasis and multiple tumors detected on DOTANOC PET scan. It was concluded that measuring superoxide anions in excised tumor tissue can be used to estimate malignant potential of CBT and can identify patients who truly require DOTANOC PET scan; without affecting the treatment, as it is an expensive investigation involving ionizing radiation and may not be available in all centres.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12070-023-03623-6.

Genetic Variants in Patients with Multiple Head and Neck Paragangliomas: Dilemma in Management

Multiple head and neck paragangliomas (HNPGLs) are neuroendocrine tumors of a mostly benign nature that can be associated with a syndrome, precipitated by the presence of a germline mutation. Familial forms of the disease are usually seen with mutations of SDHx genes, especially the SDHD gene. SDHB mutations are predisposed to malignant tumors. We found 6 patients with multiple tumors amongst 30 patients with HNPGLs during the period of 2016 to 2021. We discuss the phenotypic and genetic patterns in our patients with multiple HNPGLs and explore the management possibilities related to the disease. Fifty percent of our patients had incidental findings of HNPGLs. Twenty-one biochemically silent tumors were found. Four patients had germline mutations, and only one had a positive family history. Three out of five underwent surgery without permanent complications. Preventative measures (genetic counselling and tumor surveillance) represent the gold standard in effectively controlling the disease in index patients and their relatives. In terms of treatment, apart from surgical and radiotherapeutic interventions, new therapeutic measures such as gene targeted therapy have contributed very sparsely. With the lack of standardized protocols, management of patients with multiple HNPGLs still remains very challenging, especially in those with sporadic or malignant forms of the disease.

Contemporary management of carotid body tumors in a Midwestern academic center

BACKGROUND

Carotid body tumors are rare, neurogenic tumors arising from the periadventitial chemoreceptive tissue of the carotid body. The purpose of this study is to ascertain the presentation and preoperative risk factors associated with surgical resection.

METHODS

A single-center retrospective review of 25 carotid body tumor resections from 2002 to 2019. Demographics, periprocedural details, and postoperative outcomes were analyzed using Stata (Stata Corporation, College Station, TX).

RESULTS

Among 25 patients, 64% were women, 84% were asymptomatic, and the mean age was 49 years (range 21-79). Forty-four percent of tumors were Shamblin III. Nine patients underwent preoperative embolization but did not correlate with decreased blood loss (299 cm³ vs 205 cm³, P = .35). The 30-day death, stroke, and cranial nerve injury rates were 0%, 8%, and 32%, respectively. Cranial nerve injuries included 20% vagus, 4% hypoglossal, 4% facial, and 4% glossopharyngeal, with permanent deficits in 4% (n = 1). Mean length of stay was 3.0 days (range 1-9 days). At a mean follow-up of 12 months (range 1-63 months), there has been no recurrence.

CONCLUSION

Although carotid body tumors are uncommon in the Midwest, complete surgical resection is curative of these typically hormonally inactive tumors. Preoperative embolization did not affect blood loss, and the incidence of death, stroke, and permanent cranial nerve injury rates remained very low.

A systematic review on the genetic analysis of paragangliomas: primarily focused on head and neck paragangliomas

Head and neck paragangliomas Paragangliomas and pheochromocytomas are rare, mostly benign neuroendocrine tumors, which are embryologically derived from neural crest cells of the autonomic nervous system. Paragangliomas are essentially the extra-adrenal counterparts of pheochromocytomas. As such this family of tumors can be subdivided into head and neck paragangliomas, pheochromocytomas and thoracic and abdominal extra-adrenal paragangliomas. Ten out of fifteen genes that contribute to the development of paragangliomas are more susceptible to the development of head and neck paragangliomas when mutated. Gene expression profiling revealed that pheochromocytomas and paragangliomas can be classified into two main clusters (C1 and C2) based on transcriptomes. These groups were defined according to their mutational status and as such strongly associated with specific tumorigenic pathways. The influence of the main genetic drivers on the somatic molecular phenotype was shown by DNA methylation and miRNA profiling. Certain subunits of succinate dehydrogenase (SDHx), von Hippel-Lindau (VHL) and transmembrane protein 127 (TMEM127) still have the highest impact on development of head and neck paragangliomas. The link between RAS proteins and the formation of pheochromocytoma and paragangliomas is clear due to the effect of receptor tyrosine-protein kinase (RET) and neurofibromatosis type 1 (NF1) in RAS signaling and recent discovery of the role of HRAS. The functions of MYC-associated factor X (MAX) and prolyl hydroxylase 2 (PHD2) mutations in the contribution to the pathogenesis of paragangliomas still remain unclear. Ongoing studies give us insight into the incidence of germline and somatic mutations, thus offering guidelines to early detection. Furthermore, these also show the risk of mistakenly assuming sporadic cases in the absence of definitive family history in head and neck paragangliomas.

Pathology of the carotid space

The complex anatomy of the carotid space within a small confined area is unique to the head and neck and allows for a vast array of pathology. This paper will review the anatomy of the carotid space from the skull base to the thorax, defining its borders at multiple levels, as well as its contents. The paper will also describe the myriad of mass lesions and vascular pathologies that may occur within the carotid space. The discussion will include anatomic considerations in differential diagnoses, imaging features, and lesion characteristics across multiple imaging modalities including CT, MRI, ultrasound, and conventional angiography. Entities discussed include paragangliomas, nerve sheath tumors, meningioma, fibromuscular dysplasia, carotidynia, thrombus, dissection, pseudoaneurysm, and pathology of the deep cervical chain lymph nodes. Understanding the complex and unique anatomy of the carotid space, as well as the nuances of navigating a broad differential, will empower the reader to make an accurate diagnosis.

Multi-institutional survey of carotid body tumors in Japan

There has been no attempt to clarify the status of patients with carotid body tumor (CBT) in Japan. This multi-institutional survey analyzed patients with CBT throughout Japan by gathering information on these patients from institutions that performed head and neck surgeries. Information from a total of 150 patients from 25 institutions from the past 20 years was employed in the present survey. There were 87 females and 63 males, and their mean age was 48.0 years old. The most common chief complaint was a neck mass and the mean suffering period was 46.1 months. Eighteen patients had a family history of paragangliomas and fifteen patients had bilateral CBTs. Among the 94 patients who underwent surgery to remove a CBT, 23 patients had tumors classified as Shamblin type I, 59 had type II and 12 had type III. The most frequent feeding artery of these CBTs was the ascending pharyngeal artery. Preoperative embolization of these arteries was effective in reducing blood loss; however, the operation time in Shamblin type I and II tumors was not improved. Thus these results revealed the status of patients with CBT and their treatment throughout Japan.

Vagal Paraganglioma Presenting as a Neck Mass Associated with Cough on Palpation

A 70-year-old female presented with a neck mass and sporadic dry cough, often leading to fits of coughing severe enough to cause vomiting. The patient reported that touching the mass triggered the cough. On examination, a 2.5 cm right-sided level two neck mass deep to the sternocleidomastoid was present. Palpation of the mass immediately triggered coughing. Cross-sectional imaging proposed vagal paraganglioma as the chief differential, which was confirmed following surgical excision. The patient reported complete resolution of her severe dry cough after surgery. Vagal paragangliomas are rare neuroendocrine tumors arising from the neural crest-derived paraganglionic tissue surrounding the vagus nerve, typically presenting as a neck mass associated with hoarseness or pulsatile tinnitus. To the best of our knowledge this is a unique description in the English literature. This case is presented to aid physicians should they encounter a neck mass associated with cough. Vagal paraganglioma, although rare, should be part of the differential in such a presentation.

Glomus tympanicum tumors

Glomus tympanicum (GT) tumors are benign arising from paraganglion cells of the tympanic plexus in the middle ear. Although surgical resection remains the best option for definitive treatment of these tumors, the diagnostic and management algorithms have evolved considerably with the introduction of high-resolution computed tomography, MRI, and genetic testing.

Glomus tympanicum: a review of 115 cases over 4 decades

OBJECTIVE

To characterize the clinical presentation, surgical management, and outcomes of a large consecutive cohort of patients with glomus tympanicum (GT) tumors managed at a single tertiary referral group over 4 decades.

STUDY DESIGN

Retrospective review.

SETTING

Tertiary neurotological referral center.

SUBJECTS AND METHODS

All patients underwent surgical treatment of histopathologically confirmed GT between January 1973 and March 2014. Audiometric outcomes were reported according to AAO-HNS guidelines, and tumor stage was described using the Glasscock-Jackson classification system.

RESULTS

There were 115 patients (90.4% women; mean age, 55.2 years) who met the inclusion criteria; 38 (33.0%) cases of GT were stage I, 51 (44.3%) stage II, 10 (8.7%) stage III, and 16 (13.9%) stage IV. There were 108 (93.9%) patients who underwent gross total removal, while 7 (6.1%) received less than complete resection for advanced disease that was adherent to the petrous carotid artery, facial nerve, stapes footplate, or round window. Two patients who underwent gross total resection experienced transient facial paresis, and 1 had internal carotid injury with stroke. No patients had been diagnosed with recurrent disease at a mean follow-up of 30.4 months.

CONCLUSION

Surgery remains the treatment of choice for GT, providing a high rate of tumor control and resolution of aural symptoms with a low risk of complications. The surgical approach and extent of resection should be tailored to the patient. Gross total resection can be performed in over 90% of patients; however, leaving a limited adherent tumor remnant on the facial nerve or carotid artery should be considered with advanced infiltrative disease to prevent unnecessary morbidity.