In this case, gastric wall thickening is related to BOTH lymphomatous infiltration (in the ulcer crater) and submucosal edema (elsewhere in the lower body and antrum). This serves as a great side-by-side comparison of these important and often-confusing imaging findings. 

Tumor can be differentiated from edema due to the "soft-tissue/intermediate" attenuation, rather than the lower attenuation of edema. Enhancing soft-tissue thickening can raise the concern of infiltrative or ulcerative neoplasm, and can appropriately prepare the endoscopist prior to EGD. 

In summary this case has a combination of gastritis, submucosal edema, and malignant ulceration.