Abstract
Large extraluminal gastrointestinal stromal tumours (GISTs) are rare, with varied presentations and patient profiles. This report discusses the case of a 22-year-old female presenting with a 4-month history of lower abdominal pain, weight loss, and recurrent urinary tract infections. Imaging revealed a large intra-abdominal mass (9.3 × 15.3 × 18.9 cm) originating from the stomach, extending into the pelvis, and compressing adjacent structures. During surgery, the mass was found to arise from the lesser curvature of the stomach and adhered to the transverse colon, with non-adherent extension into the pelvis and compression of adjacent organs. A gastric wedge resection and transverse colectomy were performed with aim of achieving a R0 resection. Histopathological analysis confirmed a GIST and positive resection margins. A plan for adjuvant imatinib was initiated in accordance with the European Society for Medical Oncology (ESMO) guidelines. This article details the challenges faced in the management of such a rare presentation and highlights similar reports.