SDHB and von Hippel-Lindau disease: A potential alternative explanation for the discrepant SDHB immunohistochemistry results in case 2 is that the first hit is an undetected germline VHL mutation (e.g., intronic mutation, copy number alteration) and that the somatic VHL missense mutation in the PCC was the “second hit.” However, the RCC histology was a papillary (Fig. 2c), whereas renal tumors in VHL disease are clear cell (18, 35).