The medical name for a mole is melanocytic nevus. A nevus is usually a tan or brown lesion. Most nevi (moles) are benign (normal). They can also be dysplastic (abnormal) or cancerous (malignant melanoma). Your dermatologist will determine if a mole needs to be biopsied. Moles need to be monitored because they can change from normal to potentially problematic.
Treatment: monitor, biopsy or surgical excision