Extra-gastrointestinal stromal tumor of the omentum: a rare case report and review of the literature

• Published in: Rare tumors Vol. 4; no. 3
• Main Authors: Dimitris Fagkrezos, Zisis Touloumis, Maria Giannila, Charalampos Penlidis, Kleio Papaparaskeva, Charikleia Triantopoulou
• Format: Journal Article
• Language: English
• Published: SAGE Publishing 01-06-2012
• Subjects: EGIST; GIST; Medicine; Omentum; Oncology; Tumors
• ISSN: 2036-3603; 2036-3613
• DOI: 10.4081/4288

Gastrointestinal stromal tumors (GIST) are uncommon mesenchymal spindle-cell or epithelioid neoplasms, located mainly with higher frequency in the stomach and small bowel. Gastrointestinal stromal tumors (GISTs) represent the majority of primary non-epithelial neoplasms of the digestive tract, most frequently expressing the KIT protein a transmembrane tyrosine kinase receptor for stem cell factor. Extra-gastrointestinal stromal tumors tumors tend to present In fewer than 5% of cases, they originate primarily from the mesentery, omentum, or peritoneum. Furthermore, these extra-gastrointestinal tumors (EGIST) tend to be more common in patients greater than 50 years of age. (EGISTs) are neoplasms with overlapping immunohistological features, occurring in the abdomen outside the gastrointestinal tract with no connection to the gastric or intestinal wall. We describe a rare case of extragastrointestinal tumor of the lesser omentum and report the clinical, macroscopic immunohistological and radiologic features of an EGIST arising in the lesser omentum of a 63-year-old man, with a discussion on the clinical behavior and the prognostic factors of such lesions and a comparison with the gastrointestinal counterpart. The EGISTs in the lesser omentum can grow slowly and remain silent despite a large tumor size. In most cases a preoperative diagnosis is not possible, and the patient undergoes a surgical operation for the generic diagnosis of abdominal mass. During the intervention it is important to achieve a complete removal of the mass and to examine every possible adhesion with the gastrointestinal wall.