Аннотация
Background: Gastrointestinal stromal tumors (GISTs) are rare mesenchymal neoplasms, accounting for approximately 1–3% of all gastrointestinal tumors, with an annual incidence of 1–2 cases per 100,000 population worldwide. They arise from the interstitial cells of Cajal and are most commonly located in the stomach and small intestine. Methods: We report a case of a 39-year-old man admitted with a preliminary diagnosis of an appendiceal inflammatory mass with suspected abscess formation. Results: The patient presented with right iliac fossa pain, fever, signs of pronounced systemic intoxication and laboratory findings consistent with inflammatory syndrome. Abdominal computed tomography revealed a mass in the right iliac region with infiltration of the surrounding adipose tissue, suggestive of an appendiceal infiltrate. Emergency surgical exploration identified a tumor originating from the cecum. Radical resection of the ileocecal region with side-to-side ileo-ascending anastomosis was performed. Histopathological examination confirmed a spindle-cell variant of GIST. The postoperative course was uneventful. Conclusions: This case highlights the diagnostic challenges of atypically localized GISTs, which may clinically and radiologically mimic inflammatory conditions such as appendiceal infiltrate. Conventional imaging modalities may be insufficient for definitive differential diagnosis. Surgical resection remains the cornerstone of treatment, with histopathological and immunohistochemical evaluation establishing the final diagnosis. Early identification and complete tumor excision are essential for optimizing clinical outcomes and long-term prognosis. Adjuvant therapy with tyrosine kinase inhibitors should be considered based on individual recurrence risk.