Malignant paragangliomas associated with mutations in the succinate dehydrogenase D gene

Introduction: Malignant paragangliomas have been well described in carriers of mutations of the succinate dehydrogenase B (SDHB) gene, but have rarely been associated with mutations in the succinate dehydrogenase D (SDHD) gene. Aim: The aim of the study was to report the different clinical expression patterns of malignant paragangliomas in five patients with SDHD (D92Y) mutations observed in approximately 200 SDHD (D92Y) mutation carriers followed in our institution. Results: Metastasis and/or local tumor invasion was documented 0 (n = 2), 1, 18, and 30 yr after the initial diagnosis of paraganglioma. Malignancy was proven by paraganglioma bone metastases (n = 2), intrathoracic paraganglioma with lymph node metastases, locally invasive head-and-neck paraganglioma with destruction of the petrosal bone, and locally invasive paraganglioma of the bladder with lymph node metastases. Four of the five patients developed catecholamine excess during follow-up due to intraadrenal paraganglioma (pheochromocytoma) (n = 1), extra adrenal paraganglioma (n = 2), and presumed subclinical disease (n = 1). Conclusion: SDHD mutations (D92Y) are associated with malignant paragangliomas and catecholamine excess with remarkable interindividual variations despite the same mutation. We estimate that the prevalence of malignancy in carriers of D92Y mutations is at least 2.5%.