SDH-deficient gastrointestinal stromal tumors: paradoxical effect of imatinib

Abstract

Succinate dehydrogenase deficient gastrointestinal stromal tumors (dSDH GIST) is a unique group of GISTs with an energy metabolism defect as the key oncogenic mechanism without mutations in the proto-oncogene receptor tyrosine kinase (KIT) and platelet-derived growth factor receptor a (PDGFRA). SDH-deficiency is a result of mutations in SDHA, SDHB, SDHC, SDHD. There are three variants of dSDH GIST: sporadic dSDH GIST, Carney triad or Carney-Stratakis syndrome. dSDH GISTs are characterized by young age, female prevalence, gastric location, multiple tumors, lymph node metastases, indolent behavior and poorly response to imatinib. Despite the literature data, we report the response to imatinib in patient with dSDH GIST. 21 year old female patient presented with incomplete Carney triad (multiply gastric GIST with liver and peritoneal metastases, left lung chondroma). The patient received imatinib with clinical response in a month and radiological response in three months-cystic transformation of primary gastric tumor and liver metastases. The duration of response was 8 months.