Recurrence of fusocellular subtype GIST with SDHB mutation: A case of SDHB-loss and therapeutic challenges.

Gastrointestinal stromal tumors (GISTs) are sarcomas affecting the stomach and small intestine, with a rare subtype characterized by succinate dehydrogenase B (SDHB)-loss posing significant diagnostic and therapeutic challenges. A 62-year-old man with weight loss and abdominal pain was diagnosed with a gastric GIST showing SDHB-loss. Initial treatment with Imatinib reduced the tumor size, but surgery revealed no residual tumor. Despite adjuvant Imatinib, recurrence occurred, necessitating further surgical intervention. While GISTs typically benefit from surgery and tyrosine kinase inhibitors (TKIs), those with SDHB-loss are resistant to TKIs, requiring a different management approach. This case emphasizes the importance of surgical intervention for SDHB-deficient GISTs and the need for ongoing research into effective treatments for this subtype.