What is a circumscribed skin lesion due to an excess of melanocytes called?

A circumscribed skin lesion caused by an excess of melanocytes is referred to as a nevus. Commonly known as a mole, a nevus typically presents as a benign skin growth that can vary in color, size, and texture, depending on the concentration of melanocytes, which are the cells responsible for producing the pigment melanin. The presence of an increased number of melanocytes in a localized area contributes to the formation of this distinct lesion.

In contrast, the other terms refer to different types of skin conditions: a pustule is a small, inflamed, pus-filled blister; keratosis refers to a condition characterized by thickened skin, often due to sun exposure or other irritants; and a fissure describes a crack or split in the skin or mucous membrane. Each of these has a different underlying cause and presentation, making nevus the correct term for a lesion due to an excess of melanocytes.