Jejunal Gastrointestinal Stromal Tumour Presenting with Profound Lower Gastrointestinal Bleeding

Gastrointestinal stromal tumours (GISTs) are uncommon malignant mesenchymal neoplasms that affect the gastrointestinal (GI) system. We describe the case of a 45-year-old man who arrived at the emergency room with haemodynamic instability and profound lower GI haemorrhage. Despite early resuscitation efforts, bleeding continued, necessitating a further investigation. A sizable solid-cystic lesion in the jejunum that was heterogeneously enhancing was seen on computed tomography abdominal angiography. Urgent surgical exploration was performed, uncovering a large mid-jejunal tumour that was successfully removed, restoring haemodynamic stability. A histopathological analysis verified the presence of GIST, an uncommon jejunal occurrence. This case study emphasises the necessity of investigating GIST as a differential diagnosis in individuals presenting with significant lower GI bleeding, even if it is uncommon for their age. Surgical excision remains the cornerstone of care for localised, non-metastatic GISTs, especially in situations of severe bleeding when radiologic therapies are not possible due to haemodynamic instability.