###Human: What are the chances of a nevus being melanoma? ###Assistant: Hello. Dermoscope is of different types. Some are more good than others. Using this instrument requires a lot of practice and experience. Sometimes the person performing it cannot appreciate all the features of a particular disease. In your case, the conversion of blue nevus to melanoma is very rare. On the safe side, the doctor advised you to remove it so that no confusion left. If he or she has picked up melanoma, they would immediately treat it. You should go for excision of your nevus and histopathology will reveal the exact tissue diagnosis.