A lifetime risk of melanoma development of 6% has been estimated. The risk is greatest before age 5 and next greatest between ages 5 and 10. Early detection of melanoma is difficult in these lesions because of the deep dermal or subcutaneous origin of primary melanoma and because of the large and varied surface of the nevus. Prophylactic excision early in life can be accomplished by staged removal with coverage by split-thickness skin grafts. Surgery cannot remove all at-risk nevus cells as some may penetrate into the muscles or central nervous system below the nevus. At present there are. | Chapter 083. Cancer of the Skin Part 5 A lifetime risk of melanoma development of 6 has been estimated. The risk is greatest before age 5 and next greatest between ages 5 and 10. Early detection of melanoma is difficult in these lesions because of the deep dermal or subcutaneous origin of primary melanoma and because of the large and varied surface of the nevus. Prophylactic excision early in life can be accomplished by staged removal with coverage by split-thickness skin grafts. Surgery cannot remove all at-risk nevus cells as some may penetrate into the muscles or central nervous system below the nevus. At present there are no uniform management guidelines for giant congenital nevi. The small- to medium-sized congenital melanocytic nevus which affects approximately 1 of persons usually presents as a raised dark- to medium-brown lesion with a smooth or papillomatous surface. The border is sharp and lesions may be oriented along lines of skin cleavage. Follicular hyper- and hypopigmentation may coexist in a salt-and-pepper configuration. The lesion may have an excess of thick coarse hairs. The risk of melanoma developing in these lesions is not known but appears to be relatively small. The management of small- to medium-sized congenital melanocytic nevi remains controversial. Melanomas in small congenital melanocytic nevi appear to occur after puberty unlike melanomas that arise in giant congenital nevi and tend to occur much earlier in life. Melanomas can also arise in benign dermal and compound moles. Overall it has been estimated that for a 20-year-old individual the lifetime risk of any selected mole transforming into melanoma by age 80 years is approximately 1 in 3 164 for men and 1 in 10 800 for women. Differential Diagnosis The aim of differential diagnosis is to distinguish benign pigmented lesions from melanoma and its precursor. If melanoma is a consideration then biopsy is appropriate. Some benign look-alikes may be removed in the process of .
