Paragangliomas in an endemic area: from genetics to morphofunctional imaging. A pictorial essay

The aim of this pictorial essay is to illustrate the morphological [computed tomography (CT) and magnetic resonance imaging (MRI)], vascular (angiography) and functional (nuclear medicine) features of paragangliomas, uncommon lesions of the head and neck region and even more of the thorax, abdomen and pelvis, arising in an endemic area in northern Italy. These hypervascular, well-circumscribed masses usually have innocuous clinical manifestations as slowly enlarging soft-tissue lesions; however, more rarely, they can cause cranial-nerve palsy, particularly lesions arising near the skull base, or symptoms related to their secreting activity. Most paragangliomas are benign and their prognosis is directly related to the location of the tumour: those arising at the carotid body have the best outcome, whereas those located at the skull base have a less favourable prognosis. Angiography is required preoperatively in larger paragangliomas for surgical planning (vascular mapping) and, rarely, for preoperative embolisation. Morphological and functional imaging is also mandatory for surgical and/or radiometabolic treatment planning and follow-up.