C-kit negative PDGFRA positive bulky extragastrointestinal GIST in a 26 year old male

Background: Gastrointestinal stromal tumours (GIST) are the most common mesenchymal tumours of the gastrointestinal tract. Extra gastrointestinal GIST (EGIST) is rarely found. GIST patients are usually over 50 years of age. The diagnosis of GISTs is based on documentation of c-kit and/or platelet-derived growth factor receptors-alpha (PDGFRA) or specific c-kit mutations. Immunohistochemically (IHC) more than 90% of GISTs are c-kit (CD117) positive. PDGFRA mutations usually occur in gastric GIST. Case report: A 26 year old otherwise healthy man was admitted because of recidive atypical diffuse abdominal pain, los…