Moles are collections of pigment cells that nest in the skin, and there are many reasons for mole removal. These nested pigment cells appear darker than the surrounding skin and therefore leave a mark. Moles can be present at birth or can be acquired during one’s life. Moles can be benign or malignant. Melanoma, the most serious type of skin cancer, presents itself through the appearance of atypical, cancerous moles. Melanomas are fatal if left untreated.