Familial paraganglioma: a novel presentation of a case and response to therapy with radiolabelled MIBG.

Phaeochromocytomas (PC) and paragangliomas are disorders of the sympatho-adrenomedullary system. They are chromaffin-containing neuroendocrine tumors of neural crest origin that contain catecholamine-secreting granules: they arise from either the adrenal medulla (phaeochromocytomas) or from extra-adrenal neural crest derivatives e.g. the sympathetic chain (paragangliomas). The term paraganglioma is also used for vascular head and neck tumors derived from parasympathetic tissue, which commonly arise at the carotid bifurcation. It has been reported that some 10% of phaeochromocytomas are part of a familial syndrome, although recent data have suggested that germline mutations in known predisposing syndromes, such as multiple endocrine neoplasia type 2 (MEN2) and Von Hippel-Lindau (VHL), occur in a much higher percentage. However, familial genetic syndromes have been said to be less common in paragangliomas, although more recently described genetic syndromes may not have been considered. Thus, there is increasing evidence that mutations of subunits of the succinate dehydrogenase gene (SDHB, SDHC & SDHD) may confer susceptibility to paragangliomas and head-and-neck paragangliomas (HNPGL). We report a case of a patient with a previously published gene mutation in SDHB who had a single paraganglioma arising from the bladder with a characteristic clinical presentation, and in whom there was a positive family history of a HNPGL. He has demonstrated malignant recurrence with metastases which have been treated, so far successfully, with radiolabelled MIBG.