Review of Metastatic Paragangliomas

metanephrines, and although most cases occur sporadically, 30% of PGLs are hereditary.8 These include neurofibromatosis type 1, multiple endocrine neoplasia types 2A and 2B, Von Hippel-Lindau syndrome and succinate dehydrogenase (SDHx) gene mutations such as SDHA, SDHB, SDHC, SDHD, and SDHAF2, a gene associated with the Krebs cycle.Fractionated metanephrines in 24-hour urine or plasma free metanephrines and methoxytyramine are more sensitive markers of metastasis.These tumors are also often diagnosed as incidentalomas, or in cases with catecholamine excess and during catecholamine screening in established familial syndromes (MEN2, VHL, and NF1).9 PPGLs have been categorized into three major clusters based on transcriptional profiling 10 :