Screening for familial paragangliomas.

Paragangliomas of the head and neck are uncommon, slow-growing, multicentric and are usually benign. Ever since familial paragangliomas were first described a genetic explanation for their existence has been sought. An international collaboration finally elucidated the SDHB, SDHC and SDHD genes for three paraganglioma syndromes (PGL 4, 3, 1). A familial origin should be suspected if other family members have paraganglioma, paragangliomas are multiple, the patient is young or the patient has a vagal paraganglioma. Once familial disease is suspected the best initial screening method is by genetic testing of the patient in question. If genetic testing detects PGL 1, 3 or 4 mutations then the patient's siblings and children should be tested. All genotypically positive patients should be followed periodically as soon as detected. Surveillance is best performed with periodic radionuclide imaging and by directed magnetic resonance imaging. The purpose of surveillance is early detection and consequently earlier treatment. Abundant evidence exists that the risk of complications from surgical intervention increases with increasing tumor size. If tumors are detected and eradicated before they become large, then younger patients can be spared the dysphagia, dysphonia, dysarthria and stroke that have plagued patients undergoing surgery for these tumors.