What is a congenital nevus?
| | Fig. 41.1 A, Junctional nevi are typically small, flat, and dark brown in color. B, An intradermal nevus also may be very exophytic or papillomatous, as shown here. C, Typical halo nevus of the back demonstrating a central brownish-red papule. D, Large congenital nevus with multiple smaller congenital nevi. These lesions present a surgical challenge and a significant cosmetic problem. | A melanocytic nevus that is present at birth. For the purpose of management, any melanocytic nevus that arises during the first year of life is considered “congenital.” Congenital melanocytic nevi (CMN) are usually characterized as small, large, or giant, although there is no universally accepted definition of these categories. Small CMN are usually defined as being up to 1.5 cm in diameter, large CMN as being between 1.5 and 20 cm in diameter, and giant CMN as being more than 20 cm in diameter. Another scheme for classifying small, large, and giant CMN considers the percentage of the body surface area the lesion covers, or the ease of surgical removal and repair of the resulting surgical defect. Still another classification scheme describes giant CMN as being as large as two of the patient’s palms for lesions on the trunk and extremities, or the size of one palm for lesions on the face or neck (Fig. 41-1D). |
