Why would doctors excise an atypical nevus?

Atypical nevus: We take out an atypical nevus, because it is showing signs of possible malignancy, and needs to be verified. These signs involve irregularity of shape, mosaic of colors, lack of symmetry, rapid growth.

Cancer risk: Anytime a mole (nevus) looks a bit strange or atypical, it raises the possibility that it might be cancerous. The safe course of action is generally to exceise it and have it analyzed by a pathologist.

Prevention: Atypical nevi have a higher propensity to become cancerous. If it is excised that chance is eliminated. Sometimes we excise them to treat and diagnose at the same time. Sending the excised lesion to a pathologist for exam will tell us exactly what it is.