Four generations of SDHB-related disease: complexities in management.

SDHB mutations are linked to the familial paraganglioma syndrome type 4 (PGL4), which is associated with predominantly extra-adrenal disease and has high metastatic rates. Despite the lower penetrance rates in carriers of SDHB mutations compared to mutations in other paraganglioma susceptibility genes, the aggressive behavior of SDHB-linked disease warrants intensive surveillance to identify and resect tumors early. Patients with similar SDHB genotypes in whom the PGL syndrome manifests often exhibit very heterogeneous phenotypes. Tumors can arise in various locations, and management can be considerably different, depending on tumor site and pathology. We present a case series of five SDHB mutation carriers over four generations from the same family to illustrate the complexities in management.