SDHD and gastrointestinal stromal tumor: Metastatic risk in SDHD carriers is low and occurs in 7% to 8% of cases.15, 60 Other associated tumors include RCC and GIST, although the lifetime risk for this manifestation is very low (<1%).40, 61, 62 Pituitary adenomas are reported in five SDHD mutation carriers; in two of these, both macroprolactinomas, the presence of LoH was proven.22, 23