Other Cutaneous Nevi or Hamartomas

Nevus Verrucosus (12) appears at birth as a well-defined, raised, and verrucous plaque (Fig. 5). It may be unilateral (nevus unis lateralis) or bilateral, extensive, and

Nevus Unis Lateris
Figure 5 Nevus verrucosus of the midanterior trunk. The lesion is a congenital, verrucous, and hyperpigmented plaque with linear arrangement.
Becker Nevus
Figure 6 Becker's nevus of the right shoulder. The lesion is hyperpigmented, appears during adolescence, and may become thick and hairy.

frequently associated with skeletal or central nervous system (CNS) abnormalities (ichthyosis hystrix). Occasionally, an inflammatory component may be present in association with linear epidermal nevi (inflammatory linear verrucous epidermal nevus [ILVEN]. The histological appearance is characterized by squamous papillo-mata showing hyperkeratosis, papillomatosis, and acanthosis.

Becker's nevus (BN) appears during adolescence, is flat initially, but may become raised (13). It is pigmented and subsequently grows thick, coarse hairs. BN is more common in male patients and although the chest, shoulder, and upper arms are the usual sites of involvement, it may arise anywhere (Fig. 6). An association with other developmental abnormalities (spina bifida), multiple lesions, and familial cases have been noted. Histological examination shows mild hyperkeratosis, focal acanthosis, and a slight increase in the granular cell layer. There is a marked pigmentation of the basal layer associated with increased number of melanocytes and pigmentary incontinence. A common finding is the presence of abundant smooth muscle bundles in the dermis.

Sebaceous nevus is a congenital lesion that originates in the sebaceous glands. The tumor is a hairless yellowish plaque of variable size and warty surface. Most com- ยป

monly, it affects the scalp as a solitary lesion. Sebaceous nevus is an androgen-depen-dent tumor, which enlarges at puberty synchronous with the rest of the sebaceous d glands. It is medically important because a significant number of cases may transform >3

into syringocystadenoma papilliferum (14) or basal cell carcinoma. On histological |

examination the tumor is characterized by acanthosis and papillomatosis. Sebaceous glands are increased in numbers and are situated abnormally high in the dermis. There may be abundant cysts and the hair follicles are reduced in number or absent.

Comedo nevus (15) presents as numerous keratin-filled pits (blackheads). Most commonly, the lesion develops during childhood, although some cases may be present at birth. The most frequent location is the face but it can occur on the neck, extremities, or trunk. Tumors are single or multiple, and may be arranged in linear fashion. Histological examination shows an atrophic epidermis with numerous cysti-cally dilated hair follicles.

Nevus lipomatosus superficialis is characterized by dermal deposits of mature fatty tissue. The lesions are soft cerebriform papules and plaques, usually located on the thighs, back, or buttocks of children. Nevus lipomatosus superficialis can be present at birth or develop during the first two decades of life. Histological examination shows mature fat cells within the superficial dermis.

Connective tissue nevus (16) is a benign collection of dermal collagen and elastic fibers. The lesions are firm, smooth nodules and plaques located on the back, thighs, and buttocks. They are skin-colored and of various sizes. Tumors appear during the second decade of life and may be associated with hypertension and car-diomyopathy. Connective tissue nevi may also be present in patients with tuberous sclerosis (angiofibromas of the nose, mental retardation, seizures) and the Buschke-Ollendorf syndrome (asymptomatic, irregular, radiopaque lesions situated especially in the long bones, pelvis, hands, and feet). The characteristic histopathological change is a marked increase in dermal collagen.

How To Reduce Acne Scarring

How To Reduce Acne Scarring

Acne is a name that is famous in its own right, but for all of the wrong reasons. Most teenagers know, and dread, the very word, as it so prevalently wrecks havoc on their faces throughout their adolescent years.

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