Sporadic Multiple Gastrointestinal Stromal Tumors With Distinct KIT and PDGFRA Mutations in Two Separate Tumors: A Case Report and Literature Review.

Gastrointestinal stromal tumor accounts for approximately 80% of mesenchymal tumors and 1% to 3% of all gastrointestinal system malignancies. KIT or PDGFRA mutations are identified in approximately 92-93% of gastrointestinal stromal tumors. Both KIT and PDGFRA mutations are associated with tyrosine kinase receptor signaling pathways and are considered mutually exclusive. Herein, we report a patient with sporadic multiple gastrointestinal stromal tumors harboring mutually exclusive KIT and PDGFRA mutations in separate tumors and review similar patients in the literature.Patient PresentationA 60-year-old male patient presented with abdominal pain. Abdominal computed tomography revealed two distinct lesions in the stomach. The patient underwent distal gastrectomy, and pathological examination demonstrated that both lesions were gastrointestinal stromal tumors. Interestingly, the tumors exhibited different morphologies (epithelioid and spindle cell), distinct immunohistochemical profiles, and harbored different mutations (KIT and PDGFRA).ConclusionSporadic multiple gastrointestinal stromal tumors may have different morphological and immunohistochemical features, and they may also harbor two mutually exclusive mutations, such as KIT and PDGFRA. Recognition of this possibility is crucial for accurate diagnosis and the development of personalized therapy.