Abstract
Gastrointestinal stromal tumors (GISTs) are rare gastrointestinal neoplasms. We are presenting a 57-year-old female patient with a GIST of considerable dimensions that was deemed unresectable during the initial intervention. The patient had a previous surgical record of a peritoneal sarcomatosis tumor that covered approximately 50% of the abdominal cavity. The patient underwent surgical procedures, including exploratory laparotomy, lumpectomy, splenectomy, proximal gastrectomy, esophagogastric anastomosis, pyloroplasty, jejunostomy, and left diaphragm plasty. One of the observed results was the presence of a 50×40 cm exophytic multilobed cerebroid-like tumor in the abdomen region, specifically dependent on the gastric fundus. The primary treatment for patients without metastases is surgical removal of the tumor, with wedge resection being recommended for the preservation of organ function and quality of life postoperatively.