A rare unifocal gastric gastrointestinal stromal tumor in a young NF1 patient: A case report.

Introduction And Importance: Gastrointestinal stromal tumors (GISTs) are the most prevalent mesenchymal neoplasms of the gastrointestinal tract, predominantly associated with mutations in the KIT and PDGFRA genes. Neurofibromatosis type 1 (NF1) increases the risk of developing GISTs, particularly in younger individuals, and often presents with atypical features.

Case Presentation: A 16-year-old female with a known diagnosis of NF1 presented with severe anemia, hematemesis, and melena. Physical examination revealed multiple café-au-lait spots and cutaneous nodular masses. A contrast-enhanced CT scan showed a large mass arising from the stomach's greater curvature, consistent with GIST. The patient underwent a sleeve gastrectomy, and histopathological evaluation confirmed high-grade spindle cell GIST. Immunohistochemistry was positive for CD117, CD34, and DOG-1. Postoperative PET-CT showed no residual disease.

Clinical Discussion: GIST in NF1 patients typically presents with a multifocal pattern, but our patient exhibited a rare unifocal GIST in the stomach. The diagnosis was complicated by atypical presentation and required multimodal imaging and histopathological confirmation. NF1-associated GISTs generally lack KIT and PDGFRA mutations, rendering targeted therapies like imatinib ineffective, emphasizing surgical management as the primary treatment.

Conclusion: This case highlights the unique clinical and pathological characteristics of NF1-associated GISTs, stressing the need for vigilant assessment in NF1 patients with gastrointestinal symptoms.