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Objective: The objective of this study was to compare three-dimensional phase-contrast angiography (3D PCA), 2D time-of-flight (2D TOF), and 3D TOF magnetic resonance (MR) angiography and a proton density weighted technique in terms of their ability to detect head and neck paragangliomas., Materials and Methods: 14 patients with 29 paragangliomas were examined at 1.5 T. Three MR angiography sequences (3D PCA, 2D TOF, and multi-slab 3D TOF) and a proton density (PD) weighted sequence were reviewed by four neuroradiologists. The gold standard was digital subtraction angiography. Presence of tumor was assessed in five grades of confidence. Sensitivity and specificity were calculated after dichotomizing the results. Data was analyzed using the logistic regression method., Results: Mean sensitivity and specificity for the four observers were for PD: 72%/97%, for 3D PCA: 75%/90%, for 2D TOF: 66%/93%, and for 3D TOF: 90%/92%. Sensitivity was significantly better for 3D TOF MRA (P < 0.001). No substantial between-observer variation for tumor detection was present., Conclusion: Our results demonstrate that, using 3D TOF MRA, paragangliomas in the head and neck region can be detected with high sensitivity and specificity. Further investigation is necessary to judge the value of 3D TOF MR angiography against fat suppressed contrast enhanced T1 weighted and fat suppressed T2 weighted MR sequences to find the optimal imaging sequence for paragangliomas.

Background and Purpose: MR imaging techniques have proved their efficacy in imaging the head and neck region. In this study, we compared T1-weighted, dual T2-weighted, and fat-suppressed MR imaging and unenhanced and contrast-enhanced 3D time-of-flight MR angiography sequences for detection of head and neck paragangliomas., Methods: Thirty-one patients with 70 paragangliomas were examined. Four combinations of MR images were reviewed by two neuroradiologists: T1-weighted and dual T2-weighted fast spin-echo images, T1- and T2-weighted fat-suppressed fast spin-echo images, T1-weighted and contrast-enhanced T1-weighted fat-suppressed spin-echo images, and unenhanced and contrast-enhanced 3D time-of-flight MR angiograms. The randomized examinations were independently evaluated for image quality, presence of tumor, tumor size, and intratumoral flow signal intensity. The standard of reference for presence of tumor was digital subtraction angiography. Data were analyzed by using the logistic regression method., Results: Mean sensitivity, specificity, and negative predictive values, respectively, were assessed by the two observers to be as follows: for dual T2-weighted fast spin-echo, 74%/99%/86%; for T2-weighted fat-suppressed fast spin-echo, 70%/100%/85%; for contrast-enhanced T1-weighted fat-suppressed spin-echo, 73%/100%/86%; and for unenhanced and contrast-enhanced 3D time-of-flight MR angiography, 89%/99%/93%. Sensitivity was significantly better for unenhanced and contrast-enhanced 3D time-of-flight MR angiography (P =.000028). More intratumoral flow signal intensity was depicted with unenhanced and contrast-enhanced 3D time-of-flight MR angiography., Conclusion: A combination of unenhanced and contrast-enhanced 3D time-of-flight MR angiography is superior for detecting paragangliomas and should be added to a standard imaging protocol, especially for patients with familial paragangliomas because they are more susceptible to multicentric disease.

Opinion statement: Temporal bone paragangliomas (TBPs) are indolent, classically benign and highly vascular neoplasms of the temporal bone. There are two types of TBPs, tympanomastoid paragangliomas (TMPs) and tympanojugular paragangliomas (TJPs). The most common symptoms are hearing loss and pulsatile tinnitus. Diagnostic workup, besides conventional physical and laboratory examinations, includes biochemical testing of catecholamine and genetic testing of SDHx gene mutations as well as radiological examination. Although surgery is traditionally the mainstay of treatment, it is challenging due to the close proximity of tumor to critical neurovascular structures and thus the high risk of complications, especially in patients with advanced lesions. Radiotherapy and active surveillance have been increasingly recommended for selected patients. Decision on treatment should be made comprehensively. Curative effect depends on various factors. Long-term follow-up with clinical, laboratory, and radiological examinations is essential for all patients. [ABSTRACT FROM AUTHOR]

Glomus tumors or paragangliomas are rare benign neoplasms which are very uncommon in the head and neck region. They grow slowly from paraganglion cells, which serve various regulatory tasks in the body and form the basis of the extra-adrenal neuroendocrine system. They have benign properties, but tend to cause local invasion and expansion to adjacent anatomic structures. The majority of glomus tumor cases are incidental findings, since the clinical symptoms are mostly absent. The purpose of this paper is to distinguish the ultrasonographic features of different glomus tumors located within the neck region, based on their varying anatomical location and space occupying behavior. [ABSTRACT FROM AUTHOR]

Paragangliomas arise from paraganglion cells which serve varied regulatory tasks in the body. When these cells demonstrate neoplasia within the head and neck, they typically present in characteristic locations including the carotid space, the jugular foramen, the middle ear, and along the course of the vagus nerve. The goal of this article is to review the relevant anatomy related to head and neck paragangliomas, as well as their typical imaging characteristics on cross-sectional imaging including CT, MR, ultrasound, and nuclear medicine studies. Additionally, differential considerations, as well as relevant involvement of adjacent structures which should be conveyed to the clinician, will be discussed. [ABSTRACT FROM AUTHOR]

Background:Head and neck paragangliomas are rare. They are usually slow-growing, benign, non-catecholamine secreting tumours, traditionally treated with surgical excision. Complications of surgical excision include lower cranial nerve palsies, stroke and death.Method:A retrospective case note analysis was conducted of patients with head and neck paragangliomas treated with a watch-and-scan policy from March 2003 to September 2015, and the relevant literature was reviewed.Results:Fifteen head and neck paragangliomas were identified. None of the patients developed a new lower cranial nerve palsy or progression of their presenting hearing loss during the follow-up period. Five patients displayed an increase in maximum linear dimension of 4 mm over an average of 57.4 months. A review of the literature showed that a watch-and-surveillance scan policy is evolving as a treatment option for head and neck paragangliomas without malignant risk factors.Conclusion:Readily available surveillance scanning in head and neck paragangliomas enables the monitoring of head and neck paragangliomas, which may allow for avoidance of major surgery. [ABSTRACT FROM AUTHOR]

Purpose: Head and neck paragangliomas (HNPGLs) can relapse after primary treatment. Optimal imaging protocols have not yet been established for posttreatment evaluation. The aim of the present study was to assess the diagnostic value of F-FDOPA PET/CT and MR/CT angiography (MRA/CTA) in HNPGL patients with clinical relapse during their follow-up. Methods: Sixteen consecutive patients presenting with local pain, tinnitus, dysphagia, hoarse voice, cranial nerve involvement, deafness, or retrotympanic mass appearing during follow-up after the initial treatment of HNPGLs were retrospectively evaluated. Patients underwent both F-FDOPA PET/CT and MRA (15 patents) or CTA (1 patent). Both methods were first assessed under blinded conditions and afterwards correlated. Head and neck imaging abnormalities without histological confirmation were considered true-positive results based on a consensus between radiologists and nuclear physicians and on further F-FDOPA PET/CT and/or MRA. Results: F-FDOPA PET/CT and MRA/CTA were concordant in 14 patients and in disagreement in 2 patients. F-FDOPA PET/CT and MRA/CTA identified, respectively, 12 and 10 presumed recurrent HNPGLs in 12 patients. The two lesions diagnosed by PET/CT only were confirmed during follow-up by otoscopic examination and MRA performed 29 and 17 months later. F-FDOPA PET/CT images were only slightly influenced by the posttreatment sequelae, showing a better interobserver reproducibility than MRA/CTA. Finally, in 2 of the 16 studied patients, F-FDOPA PET/CT detected two additional synchronous primary HNPGLs. Conclusion: F-FDOPA PET/CT is highly sensitive in posttreatment evaluation of patients with HNPGLs, and also offers better interobserver reproducibility than MRA/CTA and whole-body examination. We therefore suggest that F-FDOPA PET/CT is performed as the first diagnostic imaging modality in symptomatic patients with suspicion of HNPGL relapse after primary treatment when Ga-labeled somatostatin analogues are not available. [ABSTRACT FROM AUTHOR]

Objective: To describe the potential role of dynamic contrast-enhanced (DCE) MRI in differentiating carotid space (CS) paraganglioma from schwannoma in the head and neck.Material and Methods: We retrospectively reviewed records of 126 patients who had undergone DCE-MRI between June 2008 and July 2014 and found six patients with histologically verified benign CS tumors. The images were evaluated for tumor T1 and T2 signal characteristics, flow voids, and enhancement pattern. The dynamic data were analyzed for quantitative parameters using extended Toft's model (Ktrans , Kep , Ve , and Vp ) and semiquantitative parameters based on time-intensity curve (area under curve, peak enhancement, wash-in, wash-out, signal-enhancement ratio [SER], and time for maximum enhancement [TME]). Due to the small sample size, groups were compared qualitatively.Results: Patients with CS paraganglioma (P group, n = 2) and schwannoma (S group, n = 4) were included. All tumors were hypointense on T1W imaging, hyperintense on T2W imaging, and show avid enhancement. One patient with paraganglioma had subtle flow voids. The conventional MR images were insufficient to confidently diagnose tumor type. Both paragangliomas had high peak enhancement and SER, and a short TME, while the schwannomas had relatively low peak enhancement and SER with a longer TME. Ktrans, Kep , and Ve were relatively low in the paragangliomas than in the schwannomas.Conclusion: DCE-MRI could potentially be used to assist differentiating paraganglioma from schwannoma, when diagnosis is difficult on the conventional MR imaging sequences. Simple assessment of semiquantitative parameters suffices to provide supportive information. [ABSTRACT FROM AUTHOR]

Purpose: Pheochromocytomas/paragangliomas (PHEOs/PGLs) overexpress somatostatin receptors and recent studies have already shown excellent results in the localization of these tumors using Ga-labeled somatostatin analogs (Ga-DOTA-SSA), especially in patients with germline succinate dehydrogenase subunit B gene ( SDHB) mutations and head and neck PGLs (HNPGLs). The value of Ga-DOTA-SSA has to be established in sporadic cases, including PHEOs. Thus, the aim of this study was to compare Ga-DOTATATE PET/CT, F-FDOPA PET/CT, and conventional imaging in patients with various PHEOs/PGLs with a special emphasis on sporadic cases, including those located in the adrenal gland. Design: Ga-DOTATATE, F-FDOPA PET/CT, and conventional imaging (contrast-enhanced CT and MRI with MR angiography sequences) were prospectively performed in 30 patients (8 with SDHD mutations, 1 with a MAX mutation and 21 sporadic cases) with PHEO/PGL at initial diagnosis or relapse. Results: The patient-based sensitivities were 93 % (28/30), 97 % (29/30), and 93 % (28/30) for Ga-DOTATATE PET/CT, F-FDOPA PET/CT, and conventional imaging, respectively. The lesion-based sensitivities were 93 % (43/46), 89 % (41/46), and 76 % (35/46) for Ga-DOTATATE PET/CT, F-FDOPA PET/CT, and conventional imaging respectively ( p = 0.042). Ga-DOTATATE PET/CT detected a higher number of HNPGLs (30/30) than F-FDOPA PET/CT (26/30; p = 0.112) and conventional imaging (24/30; p = 0.024). Ga-DOTATATE PET/CT missed two PHEOs of a few millimeters in size and a large recurrent PHEO. One lesion was considered false-positive on Ga-DOTATATE PET/CT and corresponded to a typical focal lesion of fibrous dysplasia on MRI. Among the 11 lesions missed by conventional imaging, 7 were detected by conventional imaging with knowledge of the PET results (4 HNPGLs, 2 LNs, and 1 recurrent PHEO). Conclusion: Ga-DOTATATE PET/CT is the most sensitive tool in the detection of HNPGLs, especially SDHD-related tumors, which may be very small and fail to concentrate sufficient F-FDOPA. The present study further expands the use of Ga-DOTATATE for all patients with HNPGLs, regardless of their genotype. Ga-DOTATATE PET/CT may be inferior to F-FDOPA PET/CT in the detection PHEOs. [ABSTRACT FROM AUTHOR]

Although anatomic imaging to assess the precise localization of pheochromocytomas/paragangliomas (PHEOs/PGLs) is unavoidable before any surgical intervention on these tumors, functional imaging is becoming an inseparable portion of the imaging algorithm for these tumors. This review article presents applications of the most up-to-date functional imaging modalities and image-based treatment to PHEOs/PGLs patients. Functional imaging techniques provide whole-body localization (number of tumors present along with metastatic deposits) together with genetic-specific imaging approaches to PHEOs/PGLs, thus enabling highly specific and sensitive PHEO/PGL detection and delineation that now greatly impact the management of patients. Radionuclide imaging techniques also play a crucial role in the prediction of possible radioactive treatment options for PHEO/PGL. In contrast to previous imaging algorithms used for either assessement of these patients or their follow-up, endocrinologists, surgeons, oncologists, pediatricians, and other specialists require functional imaging before any therapeutic plan is outlined to the patient, and follow-up, especially in patients with metastatic disease, is based on the periodic use of functional imaging, often reducing or substituting for anatomical imaging. In similar specific indications, this will be further powered by using PET/MR in the assessment of these tumors. In the near future, it is expected that PHEO/PGL patients will benefit even more from an assessement of the functional characteristics of these tumors and new imaging-based treatment options. Finally, due to the use of new targeting moieties, gene-targeted radiotherapeutics and nanobodies-based theranostic approaches are expected to become a reality in the near future. [ABSTRACT FROM AUTHOR]

Paragangliomas (PGLs) are rare vascular, neuroendocrine tumors of paraganglia, which are associated with either sympathetic tissue in adrenal (pheochromocytomas (PCCs)) and extraadrenal (sympathetic paraganglioma (sPGLs)) locations or parasympathetic tissue of the head and neck paragangliomas (HNPGLs). As HNPGLs are usually benign and most tumors grow slowly, a wait-and-scan policy is often advised. However, their location in the close proximity to cranial nerves and vasculature may result in considerable morbidity due to compression or infiltration of the adjacent structures, necessitating balanced decisions between a wait-and-see policy and active treatment. The main treatment options for HNPGL are surgery and radiotherapy. In contrast to HNPGLs, the majority of sPGL/PCCs produces catecholamines, in advanced cases resulting in typical symptoms and signs such as palpitations, headache, diaphoresis, and hypertension. The state-of-the-art diagnosis and localization of sPGL/PCCs are based on measurement of plasma and/or 24-h urinary excretion of (fractionated) metanephrines and methoxytyramine (MT). sPGL/PCCs can subsequently be localized by anatomical (computed tomography and/or magnetic resonance imaging) and functional imaging studies (123I-metaiodobenzylguanidine-scintigraphy, 111In-pentetreotide scintigraphy, or positron emission tomography with radiolabeled dopamine or dihydroxyphenylalanine). Although most PGL/PCCs are benign, factors such as genetic background, tumor size, tumor location, and high MT levels are associated with higher rates of metastatic disease. Surgery is the only curative treatment. Treatment options for patients with metastatic disease are limited. PGL/PCCs have a strong genetic background, with at least one-third of all cases linked with germline mutations in 11 susceptibility genes. As genetic testing becomes more widely available, the diagnosis of PGL/PCCs will be made earlier due to routine screening of at-risk patients. Early detection of a familial PGL allows early detection of potentially malignant PGLs and early surgical treatment, reducing the complication rates of this operation. [ABSTRACT FROM AUTHOR]

The aim of this study was to describe a previously unreported mutation in the SDHD gene, which has been linked to familial paraganglioma. Clinical data were collected from all members of the family, which had four siblings affected with paraganglioma. For the index patient, genomic DNA extraction from whole blood was performed using the High Pure PCR Template Preparation kit. The nucleotide sequence in the index patient revealed a deletion in the SDHD gene, c.165_169++14del. The loss of nucleotides in the DNA led to production of an anomalous protein. RNA analysis showed the absence of exon 2 in the sequence that corresponded to the mRNA from the index case. Genetic testing of this deletion was extended to the symptomatic and asymptomatic brothers and sisters of the index patient and other family members at risk. The deletion was detected in both symptomatic brothers, in accordance with their phenotype, but not in the asymptomatic sister. In the other asymptomatic brother (II.7) the deletion was detected and magnetic resonance angiography revealed the vascular characteristics of two tumors in both carotid bifurcations. Thus, we report a novel punctual mutation in the SDHD gene, which is related to familial paraganglioma: the deletion was c.165_169 ++ 14del. [ABSTRACT FROM AUTHOR]

To determine the clinical features, investigations, intra-operative findings, surgical approaches used and the results of the treatment for paragangliomas of the head and neck. Retrospective study of 14 cases of paragangliomas in head and neck seen over a period of 10 years including five carotid body tumors, seven glomus jugulares and two glomus tympanicums. HRCT scans and bilateral carotid angiography were done in all cases of glomus jugulare. Pre-operative embolization was done in most cases. The trans-cervical approach was used for all cases of carotid body. In three cases of Type B jugulare tumors, a post-aural tympanotomy was used. A Fisch Type A approach was done for three cases of Type D jugulare tumors. Postaural tympanotomy approach was used for both patients with glomus tympanicum. In one case of extratympanic glomus jugulare tumor with hypoglossal palsy, a neck exploration was done to isolate and excise the tumor. Five patients with carotid body tumors presented as unilateral, painless, pulsatile swelling in the upper neck. Intra-operatively, three of the tumors were classified into Shamlin's Grade II and one each into Grade III and Grade I. A carotid blow-out occurred in one of the patients with Grade II disease, which was managed. ECA resection had to be done in one case. Seven patients were diagnosed to have glomus jugulare and two with glomus tympanicum. Six glomus jugulare tumors presented with hearing loss, ear discharge and obvious swelling. Glomus tympanicums presented with hearing loss but no bleeding from the ear. On examination, tumors presented with an aural polyp with no VII nerve deficits. Both tympanicums were classified as Fisch Type A, three of the jugulares classified as Type B, two as Type D2 and one as Type D1. Tumors were found to be supplied predominantly by the ascending pharyngeal artery. In three cases of Type B jugulare tumors, a post-aural tympanotomy was used. A Fisch Type A approach was done for three cases of Type D jugulare. The transcanal approach was used for both patients with glomus tympanicum. Paragangliomas are uncommon tumors that need accurate diagnosis and skilled operative techniques. Though the surgical approaches may appear complicated, the removal provides good cure rates with minimal morbidity and recurrence. Lateral skull base approaches should be the armamentarium of every head and neck surgeon. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to characterize and quantify the vascularization and hemodynamic characteristics of head and neck tumors (HNT) with a dynamic 3D time-resolved echo-shared angiographic technique (TREAT) using the regular contrast agent (CA) bolus. Sixteen patients with HNT underwent 3D-TREAT during the CA administration on a 1.5-T magnetic resonance (MR) scanner. Using a parallel imaging acceleration factor of 2, 20 3D data sets at a temporal resolution of 2.3 s/frame were acquired. The quality of tumor delineation, vascularization type, and enhancement pattern were evaluated. Quantitative assessment included measurement of the contrast-to-noise ratio (CNR), determination of signal-intensity-over-time (SIT) curves, time-to-peak enhancement within the carotid arteries and the tumor, and the delay between both. TREAT was compared to conventional digital subtraction angiography (DSA) in six patients. Tumor delineation with TREAT was very good or good in 11/16 patients, and better with TREAT than with DSA in 3/6 cases. The CNR was significantly different for glomus tumors versus hypovascularized malignant tumors with TREAT (p=0.0001), but not on T1-weighted gradient echo (T1w GE) images. Qualitative assessment of tumor vascularization on dynamic TREAT shows good correlation (r=0.75) to quantitative SIT curves. We conclude that TREAT imaging permits the characterization of tumor vascularity and holds promise as a supplementary diagnostic tool in the differential diagnosis of HNT. [ABSTRACT FROM AUTHOR]