Current Approaches and Recent Developments in the Management of Head and Neck Paragangliomas

Abstract

Head and neck paragangliomas (HNPGLs) are rare neuroendocrine tumors belonging to the family of pheochromocytoma/paraganglioma neoplasms. Despite advances in understanding the pathogenesis of these tumors, the growth potential and clinical outcome of individual cases remains largely unpredictable. Over several decades, surgical resection has long been the treatment of choice for HNPGLs. However, increasing experience in various forms of radiosurgery has been reported to result in curative-like outcomes, even for tumors localized in the most inaccessible anatomical areas. The emergence of such new therapies challenges the traditional paradigm for the management of HNPGLs. This review will assist and guide physicians who encounter patients with such tumors, either from a diagnostic or therapeutic standpoint. This review will also particularly emphasize current and emerging knowledge in genetics, imaging, and therapeutic options as well as the health-related quality of life for patients with HNPGLs.

Update from the 4th Edition of the World Health Organization Classification of Head and Neck Tumours: Paragangliomas

“…Anatomically the vagal nerve runs near the carotid bifurcation, thus careful evaluation of the relationship of the mass to the carotid bifurcation/ carotid body region by imaging allows for this distinction. Genetically, mutations in the SDHx family of genes accounted for all of the hereditary cases in one series (89% with SDHD, 8% with SDHB, and 1% with SDHC) [41] though rare SDHAF2 have also been documented [42]. The metastatic rate may be higher for vagal PGL than other sites, 16% versus 2-6% for carotid body and middle ear PGL, with lymph nodes involvement accounting for the majority of cases [43,44].…”

15 YEARS OF PARAGANGLIOMA: Imaging and imaging-based treatment of pheochromocytoma and paraganglioma

“…By combining targeting accuracy with the steepest possible dose gradients, ablative radiosurgery should be recommended as the preferred technological choice (Taieb et al 2014b). In these cases, radiosurgical planning is guided by anatomical and functional imaging.…”

“…Delineation of biological tumor volume of tumors may be challenging, especially after surgery. The use of PET imaging using specific tracers and optimal auto-segmentation methods might help modify the extent of biological tumor volumes (gross tumor volume) for radiotherapy planning purposes (Taieb et al 2014b). It is expected that the use of specific radiopharmaceuticals in advanced PET/MRI integrated systems might also improve delineation of tumor residual masses (Blanchet et al 2014b).…”

Opacification of the middle ear and mastoid: imaging findings and clues to differential diagnosis

“…51 Dynamic MRI angiography as well as conventional angiography (which is used for tumour embolization) shows a hypervascular rapid tumour blush and early draining veins. 51 There is increased octreotide uptake on scintigraphy, and 18F-fluorodopa and 68Ga-labeled somatostatin analog uptake on PET or PET-CT. 53,55 The differential diagnosis of a glomus tympanicum includes an aberrant ICA and a facial nerve schwannoma (detailed in subsequent sections); and for a glomus jugulotympanicum tumour, a jugular foramen schwannoma, a meningioma, an endolymphatic sac tumour, and metastases. 54,56,57 However, schwannomas from the IX, X, or XI cranial nerves appear fusiform, extending superomedially with smooth jugular foramen expansion.…”