Final answer:
Nevus flammeus, or port-wine stain, is a flat, discolorated birthmark that persists throughout life and can occur anywhere on the body, mostly on the face and upper body. It does not align with the 'ABCDE' melanoma criteria. Melanoma presents differently, potentially with spots, irregular borders, and possibly as an elevated, firm, and growing lesion.
Step-by-step explanation:
Characteristics of Nevus Flammeus
Nevus flammeus, commonly known as a port-wine stain, is a type of birthmark characterized by its flat, pink, red, or purple discoloration on the skin. It varies in size, can occur anywhere on the body, but is most commonly found on the face, neck, scalp, or upper body. Unlike other marks, a port-wine stain tends to persist throughout life and may become darker or thicker over time. It is not typically associated with the 'ABCDE' criteria used to evaluate moles for melanoma, which include Asymmetry, Borders that are irregular, Color variations, Diameter greater than 6 mm, and Evolving changes in appearance.
Melanoma, on the other hand, can present as a large brown spot on the skin with darker specks, a small lesion with an irregular border and parts that appear red, white, blue, or blue-black, or a dark lesion on the palms, soles, fingertips, toes, or mucous membranes. For nodular melanoma, additional signs may include the lesion being Elevated, Firm to the touch, and Growing in size.