Clinical Heterogeneity and Long-Term Outcomes of Pediatric Gastrointestinal Stromal Tumors: A Series of Four Patients Highlighting SDH-Deficient and SDH-Intact Subtypes.

Pediatric gastrointestinal stromal tumors (GISTs) are rare, often lacking KIT or platelet-derived growth factor receptor-alpha (PDGFRA) mutations and driven by succinate dehydrogenase (SDH) deficiency. We report four pediatric patients (three females and one male) managed over a 19-year period. Two female patients had SDH-deficient tumors; one suffered metastatic relapse, illustrating the recurrent clinical course of this subtype. Of the two remaining cases, one SDH-intact female remains in remission 8 years post-diagnosis. The male patient demonstrated imatinib resistance but responded to sunitinib, facilitating gastrectomy. Despite a local recurrence managed by secondary wedge resection, he remains in remission. Comprehensive molecular profiling is essential for navigating GIST's clinical heterogeneity.