**Core Concept**
A rodent ulcer, also known as basal cell carcinoma (BCC), is a type of skin cancer characterized by uncontrolled growth of cells in the basal cell layer of the skin. It is the most common form of skin cancer and is often associated with exposure to ultraviolet (UV) radiation.

**Why the Correct Answer is Right**
The correct answer is related to the histopathological characteristics of BCC. BCCs typically exhibit a distinctive histological appearance, with features such as palisading cells, clefting between tumor cells and stroma, and the presence of a peripheral palisade of cells. The growth pattern of BCC is often described as infiltrative, with tumor cells invading surrounding tissue in an irregular manner.

**Why Each Wrong Option is Incorrect**
**Option A:** BCCs are typically aggressive and invasive. This statement is true, so it cannot be the correct answer.
**Option B:** BCCs are usually associated with exposure to UV radiation. This statement is also true, so it cannot be the correct answer.
**Option C:** BCCs are characterized by a high degree of cellular pleomorphism. This is incorrect, as BCCs typically exhibit a relatively uniform appearance with minimal cellular pleomorphism.

**Clinical Pearl / High-Yield Fact**
A key feature of BCC is its tendency to invade surrounding tissue, often leading to local destruction and disfigurement.

**Correct Answer:** C.