From the Guidelines
The workup for a head and neck paraganglioma should begin with head/neck magnetic resonance imaging (MRI) as the first modality to screen for assessment of multifocality and tumor extension. This approach is based on the latest clinical consensus guideline on the management of phaeochromocytoma and paraganglioma in patients harbouring germline SDHD pathogenic variants, published in The Lancet Diabetes and Endocrinology in 2023 1.
Key Components of the Workup
- A thorough clinical history and physical examination, focusing on symptoms like pulsatile tinnitus, hearing loss, or cranial nerve deficits
- Laboratory tests, including measurement of plasma or 24-hour urinary metanephrines and catecholamines to determine if the tumor is functional
- Imaging studies, with contrast-enhanced CT and MRI being the primary modalities; MRI is particularly valuable for soft tissue definition and vascular relationships
- Specific MRI sequences like T2-weighted images often show a characteristic "salt and pepper" appearance
- Angiography may be performed to evaluate blood supply and assist in preoperative planning
- Digital subtraction angiography can identify feeding vessels for potential embolization before surgery
- Nuclear medicine studies, such as 123I-MIBG scintigraphy or somatostatin receptor scintigraphy (Octreoscan), can help detect multifocal disease or metastases
- Genetic testing should be considered for all patients, particularly those with family history, multiple tumors, or young age at diagnosis, as up to 40% of paragangliomas are associated with germline mutations in genes like SDHD, SDHB, and SDHC
Importance of Multidisciplinary Approach
A preoperative evaluation by an otolaryngologist, neurosurgeon, or vascular surgeon is necessary to plan the appropriate treatment approach based on tumor location, size, and involvement of surrounding structures. This multidisciplinary approach is crucial for minimizing potential morbidity, especially in patients with multifocal HNPGLs 1.
Follow-Up and Surveillance
Annual blood pressure measurements, clinical assessment, and biochemical measurements are recommended to detect new PPGLs or metastases or progression 1. Whole-body MRI should be performed at least every 2-3 years to detect new SDHD PPGLs, metastases, or progression. The use of SSTR PET/CT on an individual basis can be considered to screen for disease progression in patients with non-metastatic PPGL.
From the Research
Workup for Head and Neck Paraganglioma
The workup for head and neck paraganglioma involves several steps, including:
- Biochemical testing to rule out secretory components, although this is rare in head and neck paragangliomas 2
- Imaging modalities, such as computed tomography (CT) and magnetic resonance imaging (MRI), to help in monitoring and surgical planning 2, 3
- Functional imaging with DOTATATE-positron emission tomography, 18F-fluorodeoxyglucose, or 18F-fluorohydroxyphenylalanine to rule out sites of metastases 2, 3
- Genetic testing to identify germline sequence variations in susceptibility genes, such as the gene encoding succinate dehydrogenase, which is the most common sequence variation 2, 3
Diagnostic Imaging
Diagnostic imaging plays a crucial role in the workup of head and neck paraganglioma. The following imaging modalities are used:
- CT scans to provide excellent anatomic characterization of paragangliomas 3
- MRI to provide detailed images of the tumor and its relationship to surrounding structures 3
- Gallium 68 tetraazacyclododecane tetraacetic acid-octreotate (68Ga-DOTATATE) PET/CT, which has superior sensitivity and is recommended as first-line imaging in patients with head and neck paragangliomas with concern for multifocal and metastatic disease 3
Perioperative Management
Perioperative management of head and neck paraganglioma is crucial to prevent complications. The following steps are taken:
- Preoperative management includes initiating α-adrenergic and β-adrenergic blockers to control blood pressure 4
- Intraoperative management involves close communication between the surgeons and the anaesthetist to predict and treat episodes of acute hypertension 4
- Postoperative management involves monitoring the patient's blood pressure and discontinuing antihypertensives as needed 4