Diagnostic evaluation of temporal paragangliomas
Paragangliomas are rare tumours deriving from paraganglia--small bodies of neuroendocrine tissue. Approximately 3% of paragangliomas occur in the head and neck area accounting for about 0,6% of all tumours of this region. Head and neck paragangliomas are divided into two groups: neck tumours (carotid body tumor and vagal paraganglioma) and temporal paragangliomas (jugular bulb tumor and tympanic paraganglioma). Temporal paragangliomas arise from paraganglia located in the petrous part of the temporal bone. Radiological evaluation of these lesions is essential for confirming the diagnosis and surgery planning. Most useful methods are magnetic resonance imaging and computed tomography. These modalities deliver important information about tumour location, extension and the state of the surrounding structures. Carotid angiography is a second step diagnostic method, performed in patients with jugular bulb paraganglioma. It has a diagnostic value and allows palliative or preoperative embolization of the tumor. Ultrasonographic evaluation and scintigraphy also provide advantages in diagnostic management.