Paragangliomas of the carotid body: current management protocols and review of literature

Carotid body tumor imaging: MRI, ultrasound, and elastography with surgical management

A carotid body tumor is an uncommon tumor that develops from the carotid body. Carotid body tumor, also called paraganglioma, is often benign in nature and mostly found in the neck. They make up 0.5% of all body tumors and resemble glomus jugulare, glomus tympanicum, and pheochromocytoma, which are paragangliomas of the body. We present a case of a 22-year-old male patient who presented to the medical outpatient department with complaints of swelling in the left carotid triangle for 1 month. The patient had hoarseness of voice with odynophagia and dysphagia. We found out the diagnosis of carotid body tumor when the patient came for ultrasound, and the diagnosis was later confirmed on magnetic resonance imaging. The gold standard treatment for carotid body tumors is surgery. The surgical categorization by Shamblin et al. marks a turning point in the evaluation of these tumors' resectability and is still used to predict vascular morbidity, and according to it, our patient later underwent sub adventitial tumor excision.

Presentation of metastatic carotid body paraganglioma on F-18 FDG PET/CT: a rare disease

Carotid body paraganglioma is a slow growing tumor of head and neck region. It can rarely be malignant in nature which is characterized by distant metastases on anatomical imaging. We share an interesting presentation of a malignant carotid body on F-18 FDG PET/CT in form of liver and skeletal metastases.

Case Report: Genetic Alterations Associated with the Progression of Carotid Paraganglioma

Paragangliomas (PGLs) are rare neuroendocrine tumors that can develop from any paraganglion across the body. The carotid body is the most often location of PGLs in the head and neck region. Carotid PGLs (CPGLs) are characterized by predominantly non-aggressive behavior; however, all tumors have the potential to metastasize. To date, molecular mechanisms of paraganglioma progression remain elusive. We report a case of a 38-year-old woman with metastatic CPGL manifesting as a recurrent tumor with lymph node metastasis. The tumor was fast-growing and had a high Ki-67 proliferation index. Immunohistochemical (IHC) examination and whole-exome sequencing were performed for both recurrent tumor and metastasis. A germline pathogenic splice acceptor variant in the SDHB gene was found in the patient. Immunoreactivity of the SDHB subunit was weak diffuse in both samples, indicating deficiency of the succinate dehydrogenase. Moreover, the recurrent tumor exhibited loss of heterozygosity (LOH) at the SDHB locus, that is according to Knudson's "two-hit" hypothesis of cancer causation. We also identified a rare somatic promotor mutation in the TERT gene associated with the tumor progression. Obtained results confirmed the indicative role of the germline SDHB mutation for metastatic CPGLs, as well as the potential prognostic value of the TERT promoter mutation.

The earlier, the better: The beneficial effect of different timepoints of the preoperative transarterial embolization on ameliorating operative blood loss and operative time for carotid body tumors

BACKGROUND

To explore the effect of the optimal time interval from preoperative transarterial embolization to surgery of carotid body tumors by analyzing surgery-related indicators.

METHODS

This single-center retrospective review included 103 patients and 108 carotid body tumor resections performed between June 2010 and June 2020. All carotid body tumors were divided into three groups based on interval time between transarterial embolization and surgery: 1-day group (G1), 2-day group (G2), and 3-day group (G3). Demographics, inflammatory biomarkers, periprocedural details, and postoperative outcomes were analyzed.

RESULTS

Among 103 patients, 48.54% were women, and the mean age was 37.07 years. The tumor sizes were 43.83, 44.31, and 42.84 mm in G1, G2, and G3, respectively, and the blood loss and operative time were 163.68, 331.54, and 683.68 mL, and 182.32, 216.31, and 280.79 mins with the prolonged time interval, respectively. Compared with pretransarterial embolization, the expression of white blood cells (10⁹/L) and neutrophils (10⁹/L) were obviously increased post-transarterial embolization in the three groups (G1: white blood cells 6.81 vs 9.32; neutrophils 0.54 vs 0.74, all P < .05. G2: white blood cells 7.19 vs 10.01, P = .118; neutrophils 0.54 vs 0.77, P < .05. G3: white blood cells 7.08 v. 12.37; neutrophils 0.59 vs 0.80, all P < .05), and those in G3 were significantly higher than those in G1. The incidences of revascularization, which was 30.26%, 53.85%, and 42.10%, and adverse events (26.32%, 30.77%, and 21.05%) were not significantly different among G1, G2, and G3.

CONCLUSION

The optimal time interval between preoperative transarterial embolization and surgical resection resulted as 1 day as patients in this group showed obvious lower blood loss and shorter duration of operation than patients in other groups. Both inflammation and recanalization provided support for these results at some extent.

A Rare Case of Glomus Tumor on the Mucosal Surface of Lower Lip

Glomus tumors are mesenchymal neoplasms derived from glomus bodies with rare presentations in the oral cavity. Glomus tumors present as a purple or pink vascular nodule or papule, sized <1 cm, and imitate vascular neoplasms such as hemangiopericytoma or hemangioma. Glomus tumors represent less than 2% of all benign soft tissue tumors. Only 27 cases of benign glomus tumors with oral cavity involvement have been reported to date. The most-reported oral tumors involved the lips (54.2%), followed by hard palate, gingiva, tongue, and buccal mucosa. The mean age of presentation of the labial glomus tumors is 48.7 years, with no gender predilection, in contrast to the subungual site, which occurs more in females. The etiology of the glomus tumors remains unknown. Subungual glomus tumors present as stabbing pain, cold intolerance, and tenderness of the fingertips, whereas labial glomus tumors mostly present as a painless, small, and slow-growing lesion. Treatment is surgical resection of the tumor. The recurrence rate of labial glomus tumors is unclear. In this article, we present the case of a 62-year-old man with a 2-month history of painless, soft lump on the mucosal surface of the lower left lip. Excisional resection of the tumor was performed in the clinic, and the histopathologic finding was consistent with solid glomus tumor. At 1 year follow-up there was no recurrence.

Big Carotid Body Paraganglioma: A Case Report With Successful Surgical Excision and Literature Review

BACKGROUND

Carotid body paragangliomas are rare and therapeutically challenging. Shamblin I or II carotid body paraganglioma can be removed en bloc. This operation is sometimes combined with preoperative transarterial embolization to control bleeding. However, Shamblin III carotid body paraganglioma, which is encased with carotid vessels, is difficult to remove without carotid artery ligation for excision. Sometimes, not all tumor tissues are removed during operation and residual tumor tissues remain. Here, we review a case of Shamblin III carotid body paraganglioma removal without preoperative transarterial embolization or ligation of the carotid artery. We present a successful technique for Shamblin III carotid body paraganglioma resection that reduces bleeding during the operation.

MATERIAL AND METHODS

A 74-year-old male patient who had an enlarged left neck mass for more than 20 years underwent tumor excision. The final pathology was carotid body paraganglioma. During the operation, the tumor was discovered to be encased in the bifurcation of the common carotid artery. We carefully isolated and temporarily clamped the common carotid artery to enable application of the finger dissection method to completely free the tumor from the carotid artery in a safe and bloodless plane.

RESULTS

Neither intraoperative massive bleeding nor postoperative cranial nerve deficit occurred. Favorable wound status was noted during outpatient department follow-up.

CONCLUSIONS

We describe a successful case of Shamblin III carotid body paraganglioma removal using temporary clamping of the common carotid artery and the finger dissection method.

Neuronal lineages derived from the nerve-associated Schwann cell precursors

For a long time, neurogenic placodes and migratory neural crest cells were considered the immediate sources building neurons of peripheral nervous system. Recently, a number of discoveries revealed the existence of another progenitor type-a nerve-associated multipotent Schwann cell precursors (SCPs) building enteric and parasympathetic neurons as well as neuroendocrine chromaffin cells. SCPs are neural crest-derived and are similar to the crest cells by their markers and differentiation potential. Such similarities, but also considerable differences, raise many questions pertaining to the medical side, fundamental developmental biology and evolution. Here, we discuss the genesis of Schwann cell precursors, their role in building peripheral neural structures and ponder on their role in the origin in congenial diseases associated with peripheral nervous systems.

Carotid body tumor contemporary management in a high-volume center

BACKGROUND

The aim of this study is to report our results with carotid body tumor (CBT) surgical management.

METHODS

Between 2010 and 2018, 100 CBTs (mean age: 48.0 years, range 21-80 years old) were treated in our center. The patients were classified in 3 groups according to the size: group I (<3 cm), group II (3 to 5 cm) and group III (>5 cm).

RESULTS

Surgical resection was performed in 88 patients and conservative treatment in 2 cases. Nine patients were treated for bilateral involvement and one of them was also treated again for a relapse. Postoperatively, cranial nerve injury (CNI) was significantly higher in group II [3 (8.3%) vs. 16 (31.4%) vs. 2 (15.4%); P=0.030] with no statistical differences between the CN involved. At univariate analysis for CNI, CBT group (P=0.030), maximum diameter (P=0.046), patients presenting with dysphonia (P=0.035) and dysphagia (P=0.007) and patients suffering from any intraoperative complication (P=0.047) were statistically significant. At multivariate analysis the only significant variable was CBT group II (P=0.016). For blood loss, CBT group III (P<0.001), Shamblin class III (P<0.001), Pulmonary disease (P=0.034) and surgery time (P<0.001) were statistically significant. The follow-up of 79 patients (87.8%) showed a 100% overall survival at median follow-up of 37.7 months (range 2-84.7 months) with freedom from local recurrence of 97.8% (77/79).

CONCLUSIONS

Surgical resection remains the gold standard to obtain complete recovery, although tumor size is to be considered a risk factor for CNI because large CBTs remain at high risk for CNIs.

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.

Hybrid surgery in excision of a Shamblin II glomus tumor

Glomus tumors are rare benign neoplasms originating from paraganglionic cells of the neural crest developing in the adventitious layer of the vessel. They are nonencapsulated and highly vascularized. A 64-year-old female patient was identified with a hypervascularized glomus tumor measuring 5 cm, posterior to the left carotid bifurcation and contralateral carotid occlusion. We performed preoperative embolization via endovascular access followed by direct percutaneous puncture, guided by angiography, to fill the remaining area. After embolization, surgical excision of the tumor was performed with reduced bleeding and it was easier to find the cleavage planes to adjacent structures. At late follow-up, the patient is free from tumor recurrence. The tumor was classified as Shamblin II, measuring 4 to 6 cm with moderate arterial insertion. Through this double approach we observed a relative reduction in intraoperative bleeding and improved identification of the cleavage plane, facilitating excision and avoiding surgical clamping.

Carotid Body Paraganglioma

Carotid body paraganglioma (CBP) is a type neuroendocrine tumour arising from paraganglial chief cells of carotid body. Situated at the bifurcation of the common carotid artery, it constitutes 0.5% of all body tumours. Though CBP's is most common paraganglioma of head and neck it is a rare neoplasm and requires a thorough examination for a proper diagnosis and therapeutic management. Here, we present a case of 36 year old female patient with CBP in left side of the neck.

Color Doppler Ultrasound in Diagnosis and Assessment of Carotid Body Tumors: Comparison with Computed Tomography Angiography

A carotid body tumor (CBT) is a rare, non-chromaffin paraganglioma, and its diagnosis mainly depends on imaging modalities. The aim of this study was to investigate the ability of color Doppler ultrasound (CDU) in the diagnosis and assessment of CBT based on computed tomography (CT). We retrospectively reviewed the CDU and CT features of 49 consecutive CBTs and 23 schwannomas from 67 patients and compared these findings with surgical resection specimens. The mean size of CBT lesions on ultrasound scans and CT angiography (CTA) was 3.24 cm ± 0.82 cm (range, 1.6-5.2 cm) and 3.84 cm ± 1.08 cm (range, 1.8-6.8 cm), respectively, which had statistically significant difference (t = 9.815, p = 0.000). The vascularity of CBT lesions was richer than that of schwannoma lesions (p < 0.05). Intra-lesional vascularities feeding CBT mostly arose from the external carotid artery and had spectrum characteristics including low velocity and resistance. Peak systolic velocity (PSV) and resistance index (RI) of the vasa vasorum were 39.8 cm/s ± 19.8 cm/s and 0.54 ± 0.06, respectively. There was the correlation between CTA and CDU in identifying Shamblin type I CBT lesions, while CTA technique was superior for CDU, identifying Shamblin type II and III CBT lesions. Accuracy, specificity and sensitivity of CDU in diagnosing CBTs were 87.5% (63 of 72), 82.6% (19 of 23) and 89.8% (44 of 49), respectively. Both accuracy and sensitivity of CTA in diagnosing CBTs were 100%. CDU can be useful for assessment of Shamblin's type and intra-lesional blood flow of CBTs before its metastases, while CT imaging can reveal the relationship between lesions and adjacent arteries, as well as the involvement of the skull base. CDU combined with CT imaging can be used as an optimal detection modality for the assessment and management of CBT.

Sclerosing Paragangliomas of the Carotid Body: A Series of a Rare Variant and Review of the Literature

The incidence of carotid body tumors is less than 1 in 30,000. Histologically, they present with a classic pattern of tumor cells arranged in "zellballen" or nests. A new extremely rare sclerosing subtype has been described in the literature with distinct stromal sclerosis and hyalinization, differentiating it from conventional paragangliomata. We present a case series of 3 patients with this rare variant and also discuss the diagnosis and management of carotid body parangliomas.

Papillary thyroid cancer located in the carotid bifurcation mimicking carotid body tumor

The symptoms and examination findings of masses that are located in the neck region can mimic each other. Although conventional radiological methods are useful for diagnosis, the distinction between carotid body tumors and papillary thyroid cancer may be challenging. In order to eliminate this situation that may lead to technical problems during surgery, the differential diagnosis must be made carefully. The definitive diagnostic method is pathological evaluation of the excised lesion. Herein, a patient with papillary thyroid cancer mimicking carotid body tumor is presented along with the literature.