At endoscopy, gastric ulcers appear as discrete mucosal lesions with a punched-out smooth ulcer base, which often is filled with whitish fibrinoid exudate. Ulcers tend to be solitary and well circumscribed and usually are 0.5-2.5 cm in diameter. Most gastric ulcers tend to occur at the junction of the fundus and antrum, along the lesser curvature. Benign ulcers tend to have a smooth, regular, rounded edge with a flat smooth base and surrounding mucosa that shows radiating folds. Malignant ulcers usually have irregular heaped-up or overhanging margins. The ulcerated mass often protrudes into the lumen, and the folds surrounding the ulcer crater are often nodular and irregular.