Somatic SDHB Mutation in an Extraadrenal Pheochromocytoma

Abstract

To the Editor: As many as 25% of pheochromocytomas — catecholamine-producing tumors located along the sympathetic nervous system, including the adrenals — occur in hereditary tumor syndromes that include von Hippel–Lindau disease (VHL gene),1 multiple endocrine neoplasia type 2 (RET gene), neurofibromatosis type 1 (NF1 gene), and the pheochromocytoma–paraganglioma syndrome (SDHB and SDHD genes). The last two genes are also associated with extraadrenal pheochromocytoma.2,3 To date, except for one sporadic SDHD mutation, only germ-line mutations in SDHB and SDHD have been described, even among reported mutations in these genes in apparently sporadic pheochromocytomas and paragangliomas. . . .