becker nevus

Question 1

age gender

Answer 1

BN is a distinctive asymptomatic clinical lesion that is a pigmented hamartoma, i.e., a developmental anomalyconsistingo changesinpigmentation,hairgrowth,andaslightlyelevatedsmoothver- rucous sur ace (Fig. 9-40).
■ It occurs mostly in males and in all races. It appears not at birth but usually be ore 15 years o age, although sometimes a ter this age.

Question 2

lesion

site

Answer 2

■ The lesion is predominantly a macule but with a papular verrucous sur ace not unlike the lesion o acanthosis nigricans. It is light brown in color and has a geographic pattern with sharply demarcated borders (Fig. 9-40A).
■ Commonest locations are the shoulders and the back.The increased hair growth ollows the onset o the pigmentation and is localized to the areas that are pigmented (Fig. 9-40B).The pigmentation is related to increased melanin in basal cells and not to an increased number o melanocytes.
■ Itisdi erentiated romahairycongenitalmelanocyticnevus,becauseBNisnotusuallypresentat birth, and rom ca é au lait macules because these are not hairy.
■ Thelesionextends orayearortwoandthenremainsstable,onlyrarely ading.
■ There is very rarely hypoplasia o underlying structures, e.g., shortening o the arm or reduced breast
development in areas under the lesion.