A Duodenal SDH-Deficient Gastrointestinal Stromal Tumor in a Patient With a Germline SDHB Mutation

Gastrointestinal stromal tumors (GISTs) are mesenchymal tumors of the gastrointestinal tract arising from the interstitial cells of Cajal. Succinate dehydrogenase (SDH)-deficient GISTs are a unique class of GIST defined by loss of immunohistochemical expression of SDHB, indicating dysfunction of the mitochondrial complex 2; lack of driver mutations in KIT and PDGFRA; and distinctive morphologic features and natural history. To date, all reported...