Huge Gastrointestinal Stromal Tumor (GIST) in Upper Gastrointestinal Masquerade Anaemia.

Gastrointestinal stromal tumor (GIST) represents a rare neoplasm affecting the gastrointestinal (GI) tract and is classified as a common nonepithelial tumor within the GI tract. It originates from the interstitial cells of Cajal, and GIST typically manifests with symptoms such as abdominal pain, weight loss, and gastrointestinal bleeding. This case involves a 33-year-old male who presented with GI bleeding symptoms after eight months of treatment for anemia. Oesophagogastroduodenoscopy (OGDS) revealed a singular ulcerated mass measuring 4x4cm while a computed tomography (CT) scan identified a large fundal exophytic component extending from the gastroesophageal junction to the stomach. Subsequently, the patient underwent a laparotomy and proximal gastrectomy with Roux-en-Y reconstruction, which revealed a 12x10 cm tumor located at the fundus of the stomach. This report aims to underscore the potential for misdiagnosis in the initial presentation of GIST, emphasizing the importance of raising clinical awareness in such cases.