Gastric gastrointestinal stromal tumor in a patient with neurofibromatosis type I presenting with anemia: A case report.

Background: Gastrointestinal stromal tumors (GISTs) are caused by mutations in the KIT and platelet derived growth factor receptor alpha genes in approximately 90% of cases. A minority of wild-type GISTs are associated with neurofibromatosis type 1 (NF1), an autosomal dominant genetic disease resulting from pathogenic mutations in the NF1 gene, which encodes the neurofibromin protein. NF1 patients often exhibit multi-system involvement, with café-au-lait macules and neurofibromas being characteristic symptoms. GISTs are a rare complication of NF1, with the tumors most frequently occurring in the small intestine (90% of cases), while occurrences in the stomach are rare.

Case summary: A 51-year-old woman presented to the emergency department with complaints of dizziness, fatigue, chest tightness, and dark stools. Initial examination revealed a red blood cell count of 1.99 × 10¹²/L and a hemoglobin level of 43 g/L. She underwent blood transfusions and fluid replacement to stabilize her condition. Further investigations identified typical café-au-lait macules on her trunk, limbs, and face, along with neurofibromas. Endoscopy showed coffee-colored fluid in the gastric cavity, a large submucosal elevation with an exudative covering, and ulcer formation on the gastric fundus. Exploratory laparoscopy confirmed the tumor's origin in the gastric fundus, and resection of the giant GIST was performed. Pathological analysis revealed a necrotic GIST measuring 18 cm × 14 cm, classified as high-risk, with approximately 5 mitotic figures per 10 high-power fields and no tumor at the margins. Immunohistochemistry results were CD117 (+), delay of germination 1 (+), CD34 (+), and succinate dehydrogenase complex iron sulfur subunit B intact expression. Genetic testing using next-generation sequencing confirmed an NF1 gene mutation. The patient underwent successful tumor resection and was discharged home with postoperative regorafenib therapy. A follow-up at one year showed no recurrence.

Conclusion: Given the diversity of clinical symptoms associated with NF1 and the complexity of NF1-related GISTs, surgical resection with complete tumor removal remains the preferred treatment option. However, the absence of a standardized treatment protocol for adjuvant therapy presents numerous challenges for clinicians.