Giant cell nevi are characterized by a dark, hairy verrucous appearance, and although satellite lesions are commonly seen, they are not a consistent finding.1 Giant cell nevi vary in their anatomic location and accordingly can be found in bathing suit, stocking, or coat sleeve distributions. Sometimes giant cell nevi are associated with neurofibromatosis, but not consistently so. Neurocutaneous manifestations include leptomeningeal extension, meningomyelocele, and spina bifida. Leptomeningeal melanosis is considered to be more likely in the presence of scalp or dorsal spinal cutaneous lesions. Suspicion of these warrants further investigation with magnetic resonance imaging (MRI).
Congenital nevi consist of nevus cells located in the deeper dermis and can invade skin appendages, vessels, and nerves. In contrast, acquired nevi tend to consist of nevus cells that are limited to the papillary and upper reticular dermis and do not involve skin appendages. The histologic appearance of all congenital nevi is largely similar but giant cell nevi differ in that they may have extension into muscle, bone, and dura. After birth, congenital melanocytic nevi (CMN) grow in proportion to the overall increase in body size.1
The risk of malignant transformation in congenital nevi and their preemptive management is a controversial topic on which there are many opinions. This is because many factors remain uncertain, such as the true lifetime risk of malignant change for any given lesion, and the impact of prophylactic excision in reducing development of subsequent cutaneous or noncutaneous malignancy. The lifetime risk of malignant change is probably 1–2% for small congenital nevi. The risk in medium congenital melanocytic nevi (CMN) is uncertain, and neither small- nor medium-sized CMN are likely to change before puberty. In contrast, giant CMN have a 5–10% risk of malignant transformation, and half of these will occur between the ages of 3 and 5 years. The size and site of a giant CMN as well as the number of satellite lesions appear to impact the risk of malignant transformation. Trunk lesions have a higher risk of malignant transformation as do those greater than 20 cm in diameter. When malignant transformation occurs in giant nevi, the prognosis is poor.1,2 If a diagnosis of melanoma is found following removal of a CMN, screening should be undertaken for NRSA and BRAF mutations.3
(CMN)? All of the options are reasonable reasons for surgical removal of a congenital nevus. However, the most important reason for treatment is the potential risk of malignant change. Cosmesis will often be very important to parents and patients. It is particularly important to patients as they begin to develop social awareness. The presence of large congenital melanocytic nevi (CMN) can lead to both social and behavioral consequences. The site, size, and location of the lesion and availability of tissue for reconstruction play a significant role in decision-making, especially if this makes the lesion difficult to monitor accurately. Both scarring from surgery and the original nevus can carry significant potential psychological effects, so this must be discussed in depth prior to embarking on any treatment plan.1,2
5. When planning management of congenital melanocytic nevi (CMN), which one of the following statements is correct? Early excision of small and medium congenital nevi is warranted if they are difficult to monitor (e.g., on the back or scalp) or if they have atypical features such as color variegation, abnormal borders, or growth. Nongiant nevi can be observed on an annual basis (not every 4 months) unless suspicious, in which case a diagnostic biopsy is performed instead. Giant congenital melanocytic nevi (CMN) should be excised completely as soon as possible after appropriate imaging. Reconstruction often requires a combination of tissue expansion, grafts, and flaps but is dependent on size and anatomic location. For example, giant CMN representing 1% total body surface area (TBSA) located on the trunk may be closed directly without expansion techniques. Laser and curettage are not recommended for managing CMN as they are associated with high recurrence rates.1,2
Mongolian spots are more common in races with darkly pigmented skin and can vary from a couple of centimeters to 20 cm. They are present at birth and usually disappear during childhood. In contrast, blue nevi usually appear in late adolescence and are small (less than 1 cm). They are typically blue or black and can be located on the hands, feet, head, or neck. A Spitz nevus is a red or pigmented dome-shaped papule that usually appears at birth and is commonly found on the head or neck. Excision is normally recommended. Café au lait spots are well-circumscribed, homogeneous, macular, coffee-colored lesions often seen with neurofibromatosis. A halo nevus has a white halo around the nevus due to a lymphocytic reaction and most commonly is found on the back during puberty.1–3
A sebaceous nevus is a solitary yellowish waxy congenital plaque usually found on the scalp. Alternatively, they can be located on the face, neck, or forehead. They consist of overgrown epidermis with hair follicles and sebaceous glands and are classified as a type of benign hair follicle tumor. However, they do also have a risk of malignant transformation to basal cell carcinoma (BCC) (10 or 15%) later in life and for this reason they are often treated surgically. Dysplastic (atypical) nevi often occur during or after puberty and are slightly odd-looking nevi with irregular edges, altered pigmentation, and are usually larger than 6 mm in diameter. They are often referred to as “changing moles” in order to exclude melanoma and are generally treated surgically with complete excision. Dysplastic nevi can be mild, moderate, or severely dysplastic according to their histologic appearance. Many centers will treat severely dysplastic nevi the same as in situ melanoma, i.e., with 5-mm wide excision. Nevus spilus (speckled lentiginous nevi) are tan colored macules that measure 1–4 cm in diameter and have speckling with dark brown papules or macules 1–6 mm in diameter. They usually present before age 2 as acquired lesions but may be congenital in some cases. They do not usually require intervention but may be removed surgically or treated with laser therapy. Epidermal nevi are skin lesions involving overgrowth of the epidermis. They include linear nevi which occur on the trunk and limbs, first appearing at birth or shortly after. They comprise of tan or brown colored warty macules or papules, without plaques or hair. Again surgery or laser treatment is often performed for these lesions. Basal cell carcinomas are slow-growing, nonmelanoma skin cancers seen in older age groups. They almost never metastasize and have an association with sebaceous nevi as described above. Their management may be surgical, topical, or with radiotherapy depending on their subtype.1–4
Melanocytic nevi occurring in infancy or during the first 2 years of life are classified as tardive congenital melanocytic nevi (CMN) or congenital nevus-like nevi (CNLN). They are clinically and histologically indistinguishable from CMN. Therefore, the two subtypes are treated in the same manner with regular observation or surgical excision. The rate of growth itself is not different; it is purely that presentation is later.1,2
expected? Melanocytic proliferation within the brain parenchyma or leptomeninges (the combined pia and arachnoid mater) is described as neuromelanosis. When seen in combination with congenital melanocytic nevi (CMN) this is called neurocutaneous melanosis and raised intracranial pressure can be a problem for such patients. Symptoms of this include headache, photophobia, lethargy, and recurrent vomiting. Ultimately this condition can result in seizures, developmental delay, cranial nerve palsies, sensorimotor deficits, and bladder and bowel dysfunction. Where there is central nervous system (CNS) involvement, patients are usually symptomatic by 2 years of age. Investigation with magnetic resonance imaging (MRI) is warranted in the first 4 months of life. Unfortunately, there is little treatment that can be offered other than managing intracranial pressure issues. In general, where neurologic symptoms are present, prognosis is very poor. The other options listed are not specifically related to this condition.1–3
The nevus of Ota has an onset at birth or within the first year of life and during puberty. It is especially common in Asians and blacks. It appears as a blue-brown unilateral periocular macule varying in size from a few centimeters to one which affects half of the face and follows the trigeminal nerve distribution. The nevus of Ito usually appears at birth and is typically seen in Asians and blacks. It appears as a large blue- brown lesion on the posterior shoulder innervated by the supraclavicular and lateral cutaneous brachial nerves. Spitz nevi are red or pigmented, smooth, dome-shaped papules with telangiectasia measuring about 8 mm in diameter. They usually appear at birth and are also called juvenile melanoma. They are best managed with surgical excision for both diagnostic and therapeutic purposes. Tardive congenital nevi are congenital nevi that develop within the first 2 years after birth. They are managed the same as other congenital nevi with either monitoring or removal as they carry a small risk of malignant transformation. A Mongolian spot is a steel-blue macula present at birth or during first few weeks of life located in the lumbosacral area. Size of these lesions ranges from a few centimeters to 20 cm or more. They are more common in darkly pigmented skin and usually disappear in early childhood.1–4
A Becker’s nevus (pigmented hairy epidermal nevus) is a late-onset birthmark which is first observed in adolescence as a tan to brown hairy lesion most commonly affecting one’s shoulder. The hairs and pigmentation are often treated with laser therapy. Café au lait spots may be present at birth, but usually develop in childhood. They are well-circumscribed, oval macular lesions that have a homogenous milky coffee color. They are often associated with neurofibromatosis. Halo nevi are small, brown-colored nevi with a surrounding white halo. The white halo represents a lymphocytic reaction and such lesions are most commonly found on upper backs of teenagers. Dysplastic nevi most often develop after adolescence and appear as an irregular, brown-colored skin lesion with areas of different pigmentation, and are most commonly found on the trunk. They are usually larger than 6 mm and should be treated with surgical excision. Spitz nevi are red or pigmented, smooth, dome-shaped papules with telangiectasia measuring about 8 mm in diameter. They usually appear at birth and are also called juvenile melanoma. They are best managed with surgical excision for both diagnostic and therapeutic purposes.1–4