SDHB and metastatic neoplasm: In order to better define the subgroup of PPGL patients who may benefit from treatment with SSTR-based therapies, this retrospective study investigated the association of SSTR2 immunoreactivity with SDHB immunoreactivity, mutational status, and metastatic disease, and, additionally, evaluated the response of metastatic PPGLs (mPPGLs) with or without known germline and/or somatic mutations to SSTR-based therapies.