A Panoply of Nevi

Case 1: An area of pigment loss in the skin and surrounding hair is noted on the head of a 10-year-old boy. Examination of the vertex of the scalp reveals a nevus encircled by depigmentation. Can you identify this lesion? Case 2: During a routine skin examination, a suspicious-looking pigmented lesion is noted on the upper back of a 27-year-old man. The 4-cm, irregularly shaped lesion is composed of multiple, small dark brown macules. Is this lesion likely to be malignant?Case 1: This is a halo, or Sutton, nevus. The differential diagnosis of a depigmented area includes vitiligo and pityriasis alba; however, the central location of a pigmented lesion in a round, sharply demarcated area of almost complete pigment loss is unique to a halo nevus. The lesion gradually resolves, with repigmentation of the skin and hair and disappearance of the nevus. These nevi are usually benign; however, evaluate the central nevus using the "ABCD" rules for melanoma detection (Table). Case 2: This is a nevus spilus, a type of congenital nevus. Because of the lesion's unusual clinical appearance, the differential diagnosis includes malignant melanoma. However, a nevus spilus is a benign lesion that is associated with a very low rate of malignant transformation. The patient also has multiple darkly pigmented nevi on his back with a background of freckling.Case 3: The parents of a 6-year-old boy are concerned about a small reddish lesion on the lateral side of their son's nose. The lesion has grown slightly larger and more prominent over time. What is your clinical impression?Case 3: A spider angioma, or nevus araneus, is a benign lesion caused by dilated arterioles that supply radiating surface telangiectases. The diagnostic sign is a central, often pulsatile, red papule; when the center is compressed with a pen point or other blunt, narrow object, the entire lesion blanches. These features help distinguish spider angiomas from simple telangiectases. In children, spider angiomas typically fade over time. They can be treated by electrocautery or laser surgery, if desired for cosmesis. Spider angiomas can also be induced by various factors, including exogenous estrogen intake, alcoholism, pregnancy, or thyrotoxicosis.Case 4: Two skin-colored papules--one at the medial right eyebrow, the other just above the lateral half of the same eyebrow-have been present for years in a 34-year-old woman. The asymptomatic lesions may have enlarged with time. What are these lesions?Case 4: Case 4: Both papules were removed by shave biopsy with good results. Histopathologic examination revealed nevus cells confined to the dermis in nests or cords; 2 intradermal melanocytic nevi were diagnosed. An intradermal nevus is a common melanocytic nevus. Most of these usually dome-shaped, nodular, or polypoid lesions occur in adults. The nevi are often flesh-colored, or they can be slightly pigmented. Hairs may protrude through the surface. Very rarely, a melanoma may develop within an intradermal nevus; because of this potential, histopathologic examination of these nevi is prudent.Case 5: A large, well-defined, hypopigmented macule with an irregular border is noted on the lower back of a 58-yearold woman; in addition, a few smaller macules appear beyond the border. The patient reports that the lesion has been present since birth and has not changed. Do you recognize this lesion?Case 5: Nevus anemicus is a rare congenital lesion that is more common in women than in men. It is usually located on the chest or back. When the nevus is rubbed, a flare does not appear; however, a normal flare will occur outside the lesion. It is thought that the hypopigmentation is secondary to relative vasoconstriction caused by increased blood vessel sensitivity to catecholamines. Nevus anemicus is most frequently confused with tinea versicolor or vitiligo. Tinea macules generally feature scale; if the diagnosis is in doubt, a potassium hydroxide preparation can rule out this fungal infection. A Wood lamp examination accentuates the depigmentation of the multiple spots of vitiligo, which characteristically involve the hands, feet, and penis.Case 6: A 29-year-old woman presents for evaluation of a large blue-gray to brown patch that surrounds her left eye and involves the sclera. What treatment will you recommend?A nevus of Ota is a hamartoma of dermal melanocytes. The lesion may be present at birth, appear during the first few years of life, or arise in early adolescence. These nevi are more common among Asians and African Americans than among white persons. The male-to-female ratio is 4:1. A nevus of Ota presents as a unilateral blue-brown, speckled patch, usually involving the malar region, periorbital area, temple, or forehead. The nevus may also affect the eye, as in this patient. Ocular muscles, periosteum, oral and buccal mucosae, and the retrobulbar fat may also be involved. These lesions enlarge slowly, become deeper in color, and