Benign paragangliomas

Paraganglia are specialized neural crest-derived cells (chromaffin cells) that are divided into sympathoadrenal and parasympathetic paraganglia [14, 22]. The sympathoadrenal paraganglia are symmetrically distributed along the paravertebral axis from high in the neck near the superior cervical ganglion to the abdomen and pelvis. Small sympathoadrenal paraganglia can also be associated with organs such as the urinary bladder and prostate gland. The parasympathetic paraganglia are primarily localized to the skull base and neck. Paragangliomas are rare tumors that arise from extra-adrenal paraganglia; they represent 10-18% of all chromaffin tissue-related tumors [5, 40], which are reported at a rate of 2-8 cases per million per year [5, 34]. The diagnosis, localization, and treatment of paragangliomas offers potential cure of symptoms associated with functional tumors, prevention of a lethal hypertensive paroxysm,prevention of morbidity from mass effects, and the early diagnosis of malignant tumors [41].