Voluminous abdominal gastrointestinal stromal tumor of unknown origin manifested with bleeding in a young man: synchronous management of the emergency and oncological approach-case report.

Gastrointestinal stromal tumors (GISTs) are rare tumors of the gastrointestinal tract, which cover about 1-2% of gastrointestinal neoplasms with an unadjusted incidence of around 1/100,000/year. They are also the most common non-epithelial neoplasms of the gastrointestinal tract and they are associated with a high rate of malignant transformation. They are more common in the stomach (40-60%) while a minor part repeatedly involves jejunum/ileus (25-30%), duodenum (5%), colorectal (5-15%) and esophagus (<1%). There are also much rarer extragastrointestinal stromal tumor (EGIST): these tumors have immunohistochemical and molecular characteristics similar to GISTs and for this reason, they are called this way, EGIST can involve retroperitoneum, mesentery, and omentum, without affecting the gastrointestinal tract. The clinical presentation depends on the primary localization of the neoplasm, however in 18% it is asymptomatic, and it is accidentally discovered during endoscopies, radiological examinations or surgical operations performed for other reasons, especially if it is small in size. More often, they are associated with non-specific symptoms such as early satiety, nausea or vomiting. Gastrointestinal bleeding is the most dangerous complication, often necessitating emergency surgery. The purpose of this case report is to describe our experience in the management of a young patient with gastrointestinal bleeding caused by an unknown voluminous retroperitoneal GIST with metastatic progression using a combined endovascular embolization and debulking-surgery approach for emergency and imatinib therapy combined with radiofrequency for the oncological approach. GIST requires multidisciplinary management, which improves both prognosis and quality of life.