Malignant change in nevus is characterised by-a) Darkeningb) Hemorrhagec) Itchingd) Increase in Size

**Core Concept**
Malignant transformation in a nevus refers to the process by which a benign melanocytic lesion, such as a melanocytic nevus, undergoes genetic and histological changes to become a malignant melanoma. This transformation is a result of mutations in genes that regulate cell growth, division, and death, leading to uncontrolled proliferation of melanocytes.

**Why the Correct Answer is Right**
The correct answer is **Increase in Size**. Malignant transformation in a nevus is often accompanied by an increase in size, which is a key clinical indicator of potential malignancy. This is because malignant cells grow and divide more rapidly than benign cells, leading to an increase in the size of the lesion. As the nevus grows, it may also become more irregular in shape, develop new colors, or exhibit other warning signs of malignancy. In contrast, benign nevi tend to remain stable in size and shape over time.

**Why Each Wrong Option is Incorrect**
**Option A:** Darkening is a common feature of benign nevi, particularly in response to sun exposure or hormonal changes. While darkening can be a concern, it is not a specific indicator of malignant transformation.

**Option B:** Hemorrhage is not a characteristic feature of malignant nevi. While nevi can become inflamed or irritated, leading to bleeding, this is not a reliable indicator of malignancy.

**Option C:** Itching is a symptom that can be associated with a variety of skin conditions, including benign and malignant lesions. However, itching is not a specific indicator of malignant transformation in a nevus.

**Clinical Pearl / High-Yield Fact**
The ABCDE rule is a useful clinical tool for evaluating the risk of malignancy in a pigmented skin lesion. The rule stands for Asymmetry, Border irregularity, Color variation, Diameter greater than 6mm, and Evolving shape or size. If a lesion exhibits any of these characteristics, it should be evaluated further by a dermatologist.

**Correct Answer: D. Increase in Size**