Final answer:
A lentigo is a type of skin spot (option c) that typically appears as a brown, tan, or black spot with a clearly defined edge. While benign, any changes in skin spots should be examined due to the potential risk of skin cancer, especially following sun exposure.
Step-by-step explanation:
The medical term lentigo refers to a type of skin spots that are typically brown, tan, or black. Lentigines, or lentigos, are characterized by their clearly defined edges and can vary in size. They are usually caused by sun exposure and can be found on the skin of people of any age, often appearing on areas of the body that have been exposed to the sun, such as the face, hands, and arms. While lentigines themselves are benign spots, it is important to monitor any changes in skin spots as they can sometimes be confused with skin cancers, which can be alarming given that one in five Americans will experience some type of skin cancer in their lifetime.
Moles, which are larger masses of melanocytes, are benign but should also be watched for changes that might indicate the presence of cancer. When examining skin spots for potential skin cancer, you can refer to the ABCD mnemonic: Asymmetry, Border irregularity, Color that is very dark, and Diameter that is relatively large. If you spot changes, especially after excessive sun exposure which can lead to DNA damage and potential cancerous lesions, it is critical to seek medical advice.