The complexity of
GIST molecular biology.
WT GIST could be firstly divided two main group according to the SDHB immunohistochemical status: SDHB
IHC+ (including NF1-mutated GIST and sporadic KIT
WT GIST with or without KRAS/BRAF mutations) and SDHB
IHC- or SDH-deficient GIST. The latter could be further divided according to the SDHA immunohistochemical status: SDHB
IHC- GIST (pediatric type or young adult GIST characterized by germline or somatic inactivating SDHA mutations) and SDHB
IHC+ GIST (including Carney-Stratakis Syndrome-related GIST, characterized by germline or somatic inactivating SDHB, −C, −D mutations, Carney Triad-related GIST that lack SDHx mutations, and sporadic KIT
WT GIST, characterized by germline or somatic inactivating SDHB, −C, −D mutations and SDHA mutations, reported in only three cases . In red the subset of KIT
WT GIST referred to as quadruple
WT GIST (KIT
WT), that represent the subject of this study.