Do You Know Your Nevi? Part 1

Case 1:

The parents of a 3-year-old girl seekmedical evaluation of the nodules ontheir daughter's back. The lesionshave been present since birth andhave grown with the child.What is your clinical impression?

Case 2:

A pigmented lesion has been presenton a teenager's back for a year, butthe surrounding circle of depigmentationdeveloped recently after a sunburn.The lesion and surroundingskin are neither pruritic nor painful.Is biopsy warranted?

Case 1:

This is

nevus lipomatosus;

the group of soft yellow nodules havecoalesced to form a plaque over thepatient's sacrum. These nevi have apredilection for the lower back andthe upper thighs. This diagnosis ismade clinically and, if necessary, canbe confirmed by a biopsy.Nevus lipomatosus results fromthe abnormal presence of adipose tissuein the dermis. Typically, these benigntumorlike lesions are noted atbirth or in childhood; over time, theycan grow and may become pedunculated.This nevus can be removed bysimple excision.

Case 2:

This is a

halo, or Sutton, nevus.

These lesionsusually arise during adolescence; multiple halo nevi areoften present.Initially, a halo of depigmentation appears aroundan existing nevus. The central nevus often disappears overtime, and an area of depigmentation remains. This areamay eventually repigment.Histologic examination of a halo nevus reveals astriking lymphocytic infiltrate admixed with nevus cells inthe dermis and at the dermoepidermal junction, with aloss of epidermal melanocytes in the depigmented haloarea.Frequently, these nevi are first noted during the summer because the halo--unlike adjacentnormal skin--does not tan. These lesions are usually benign when seen in adolescents; however,use the "ABCD" lesion assessment criteria

(Table)

to determine whether a biopsy is warranted. Inan adult, the development of an isolated pigmented lesion surrounded by a halo can be benign,but excision is recommended to rule out the remote possibility of a halo melanoma.

REFERENCE:

1.

Friedman RJ, RigelDS. The clinical featuresof malignantmelanoma.

DermatolClin.

1985;3:271-283.

Case 3:

A 2.5 * 8-cm hairy, pigmented lesionis noted on a 15-year-old boy's lowerleg; the lesion has been present sincebirth. The size of the birthmark hasnot increased disproportionately overtime.Is it likely that this lesion ismalignant?

Case 4:

An irregular pale white macule hasbeen present on the trunk of an8-year-old boy since birth. The area isasymptomatic. The patient has noother similar lesions.What do you suspect--and howwill you narrow the differential?

Case 3:

The patient has a

congenital hairy nevus.

Congenital nevi are presentat birth and can vary in size from a few millimeters to many centimeters. Thelesions are usually brown or black but may be red or pink. They are often flator barely raised at birth and thicken with age. The surface of the nevus maybecome nodular; the hair that can arise is usually coarse.Giant congenital nevi are defined as larger than 20 cm. One that covers alarge portion of the trunk is referred to as a bathing trunk nevus.The risk of melanoma in small congenital nevi is controversial; however,most experts consider it to be relatively low. Because giant hairy congenitalnevi pose a higher risk of melanoma, referral to a surgeon for consideration ofremoval is warranted. Small congenital nevi may be followed by close observation,or they may be excised to eliminate any risk of malignant transformation.

FOR MORE INFORMATION:

• Weedon D. Skin Pathology. London: Churchill Livingstone; 2002:815-816.

Case 4:

Nevus depigmentosus

is a birthmark that occursin approximately 1 in 125 persons. It can present as asingle, well-demarcated hypomelanotic macule that rangesfrom 0.5 to 10 cm. Less often, the distribution is segmentalor systematized (multiple streaks following the lines ofBlaschko).A nevus depigmentosus can be distinguished from anevus anemicus by diascopy, which is performed bypressing a clear glass slide on the lesion. The boundary of the nevus depigmentosus remains visibleduring this procedure, whereas the border of the nevus anemicus disappears.The differential diagnosis includes the ash-leaf spot of tuberous sclerosis. When a childpresents with multiple lesions and/or additional signs or symptoms that suggest tuberous sclerosis,such as seizures or facial angiofibromas, further evaluation, including diagnostic imaging, is warranted.The presence of a single lesion in an asymptomatic child requires observation only.Because this patient's nevus was an isolated lesion, follow-up and reassurance were sufficient.

FOR MORE INFORMATION:

• Ackerman AB, Kerl H, Sanchez J. A Clinical Atlas of 101 Common Skin Diseases: With Histopathologic Correlation. New York: ArdorScribendi; 2000.
• Dover JS, Jackson BA. Pocket Guide to Cutaneous Medicine and Surgery. Philadelphia: WB Saunders Co; 1996.

Case 5:

A 32-year-old man presents with ahypopigmented lesion on his leftflank. The lesion has been presentsince infancy.What steps will you take todetermine the cause of the area ofdepigmentation?

Case 6:

An 8-year-old girl is brought to the office for evaluation of a lesion on theback of her neck, which was first noted a few years earlier. Examination revealsmultiple comedones grouped together.Can you identify this lesion?

Case 5:

When pressed with a glass slide, a

nevus anemicus

becomes indistinguishablefrom the surrounding normal skin. Friction or applications of heator cold to the nevus do not produce erythema within the lesion; however,the surrounding skin does respond. The absence of erythema is attributed toblood vessel constriction that is secondary to increased blood vessel sensitivityto catecholamines.A Wood lamp examination accentuates patches of vitiligo, which is inthe differential; whereas a nevus anemicus is invisible under the lamp. No treatmentis necessary for this nevus.

Case 6:

A nevus comedonicus

is apatch-like collection of flesh-coloredpapules, each with a comedo-likedilated center. It may be congenital oracquired. The face, neck, upper arm,and chest are sites of predilection.These lesions are usually of cosmeticconcern only.Because of the typical comedonallesions, these nevi are generallyrelatively easy to diagnose. Thedifferential includes nevus sebaceus,molluscum, and acne; if the diagnosis is in doubt, a punch biopsy may be performed.Removal for cosmesis can be accomplished by excision or carbon dioxidelaser ablation.

Case 7:

For as long as he can remember, a 40-year-old man has had a red-purplediscoloration on the right side of his face, head, and neck. He has never hadany symptoms associated with this nevus.What are your thoughts about this lesion?

Case 7:

A

port-wine stain

(or

nevus flammeus

)is a congenital vascularmalformation of mature dilated capillaries in the entire dermis; the condition isnot genetically transmitted. Most often, these lesions occur on the face butmay appear on any part of the body. They need to be differentiated from benignflame nevi, which commonly occur in newborns and are known as"salmon patches," "stork bites," and"angel kisses." Port-wine stains areflat and smooth at birth and--unlikebenign flame nevi, which fade spontaneouslyover a few years--tend to becomepapular, nodular, and darkerwith age.A port-wine stain can occur as anisolated finding or as part of a syndrome.When a stain involves bothsides of the face or both the upperand lower eyelids (the first branch ofthe trigeminal nerve), there is a riskof vascular malformations of the ipsilateralleptomeninges with associatedmental retardation, glaucoma, andseizures (Sturge-Weber syndrome)and congenital cataracts.The disfigurement caused byport-wine nevi is often psychologicallydevastating. Makeup applied to affectedareas may significantly improve apatient's appearance and self-esteem.Tunable dye laser therapy performedin early childhood is the most beneficialtreatment.