SDHB and metastatic malignant neoplasm in the lymph nodes: In KIT/PDGFRA wild-type GISTs, approximately 50% of patients are negative for SDHB by immunohistochemistry (11), termed SDH-deficient GISTs, which have several special clinical manifestations, such as earlier age of onset, multiple lesions, most of them originating in the stomach, and more prone to lymph node metastasis (12, 13).