Malignant head/neck paragangliomas. Comparative study.

BACKGROUND The objective of this study was to report 11 cases of malignant head and neck paraganglioma and to compare their epidemiological, clinical, and genetic characteristics, their natural history and their treatment with those of a series of 131 benign paragangliomas. PATIENTS AND METHODS Retrospective analysis of 142 patients with head and neck paraganglioma managed between 2001 and 2008. Age at the time of diagnosis, gender, primary tumour site, presence of other non-head/neck paragangliomas and/or metastases diagnosed by imaging (CT, MRI, Octreoscan or (18)F-FDG PET), histology, urinary catecholamine and metanephrine levels, family history, and genetic test results were recorded. RESULTS This series comprised 131 benign head and neck paragangliomas, mostly observed in women with a mean age at diagnosis of 45 years and a predominance of tympanojugular sites (followed by carotid and vagal sites) with 5% of secreting tumours and 20% of multifocal tumours. Eleven patients (7.7%) with a 1:1 sex ratio presented criteria of malignancy. These patients, with a lower mean age (38 years), predominantly presented carotid lesions with a higher rate of secreting and multifocal tumours, 27% and 46% respectively. The main sites of metastases were bone and lymph nodes. No tympanic paragangliomas were observed. CONCLUSIONS Malignant paragangliomas are mainly observed in young patients with multifocal tumours, particularly carotid tumours, and are predominantly related to subunit SDH-B mutation. The work-up in these high-risk patients must include whole body scintigraphy and spine MRI. Malignancy is not necessarily associated with a poor short-term prognosis due to the slow course of the disease.