[Head and neck paragangliomas: revision of 89 cases in 73 patients].

Introduction: Paragangliomas (PGL) are uncommon neuroectodermal tumours. PGL are usually clinically benign tumours, although metastasis has been reported and invasive growth can occur in adjacent tissues (<10 %). Mutations in SDHB, SDHC, and SDHD, which encode sub-units of mitochondrial complex II (succinate dehydrogenase), play an important role in the pathogenesis of these tumours.