The Role of Endoscopy in the Diagnosis of Gastric Gastrointestinal Stromal Tumors

Excerpt

Gastrointestinal stromal tumor (GIST) is a rare cancer but the most common sarcoma in the gastrointestinal tract, arising most frequently in the stomach.1 Its clinical incidence is estimated to be 10 million/year. The standard treatment of primary and localized GIST is macroscopically complete resection. Gastric GIST shows significantly better prognosis after surgery than non-gastric GIST. GIST is considered to be originated from mesenchymal cells potentially differentiating into the interstitial cells of Cajal and mostly occurs in the intermuscular layer.1,2 Subsequent progression of GIST may be intraluminal, extrinsic, or bidirectional in the gastric wall. Practically, all tumors are covered by the normal mucosa and appear as submucosal (or subepithelial) tumors (SMTs) in endoscopic and fluoroscopic examinations. Hence, GIST is not directly visualized by endoscopy without using endoscopic ultrasound (EUS), and pathological specimens are not always obtained by conventional endoscopic biopsy. Because of its neoplastic behavior and localization, GIST may be sometimes asymptomatic until advanced stages and its histologic diagnosis prior to surgery is still challenging. The confronting problems include distinguishing the tumors with malignant behaviors and courses, which require treatment, from those with benign ones, which afford a watch-and-wait approach. …