**Core Concept**
Malignant gastric ulcers, also known as gastric cancer, arise from the malignant transformation of gastric epithelial cells. This condition is characterized by uncontrolled cell growth, invasion of surrounding tissues, and potential metastasis to distant organs.

**Why the Correct Answer is Right**
Malignant gastric ulcers typically present with deep, excavated ulcers that are often associated with a thickened, irregularly-shaped rim. These ulcers tend to occur in the upper body of the stomach, particularly in areas with chronic gastritis or intestinal metaplasia. The presence of malignancy is often suspected when there is a failure to heal after several weeks of medical therapy or when there is an atypical presentation, such as a large, irregularly-shaped ulcer.

**Why Each Wrong Option is Incorrect**
**Option A:** This option might be a distractor if it lists a common feature of benign gastric ulcers, such as a well-defined, rounded edge. However, the question asks for an exception (A/E), so this option would be incorrect if it describes a characteristic of malignant ulcers.
**Option B:** This option might be a distractor if it mentions a feature that is not specific to malignant gastric ulcers, such as anemia or weight loss. However, these symptoms can be associated with both benign and malignant conditions.
**Option C:** This option might be a distractor if it lists a feature that is not typically associated with malignant gastric ulcers, such as a large amount of bleeding. However, this option would be incorrect if it describes a characteristic that is more commonly associated with benign ulcers.

**Clinical Pearl / High-Yield Fact**
A key clinical pearl is that patients with malignant gastric ulcers often present with a history of chronic gastritis, particularly with intestinal metaplasia, and a failure to heal after several weeks of medical therapy. Additionally, the presence of a thickened, irregularly-shaped rim on endoscopy is highly suggestive of malignancy.

**Correct Answer: C. A large amount of bleeding.**