This congenital lesion is composed of hamartomatous sebaceous glands and abortive hair follicles. It usually presents at birth as a yellow nodule or pebbled, hairless plaque on the scalp, forehead, or neck. Figure 22-1 shows the color and shape of the congenital lesion. With the loss of the effect of maternal hormones during the first few months of life, the lesion may quickly flatten and lose its distinctive color. During puberty, the nevus sebaceus again becomes raised, yellow, and verrucous. After this change, and usually during adulthood, nevus sebaceus may give rise to a wide variety of benign and malignant neoplasms. These include basal cell hamartomas, keratoacanthomas, syringocystadenoma papilliferum, basal cell epitheliomas, and, rarely, squamous cell carcinomas.
Figure 22-3 is illustrative of a syringocystadenoma papilliferum which may arise in a nevus sebaceous and have the typical cockscomb appearance. This is a benign neoplasm. Figure 22-4 shows another nevus sebaceus on which basal cell carcinoma has developed. In this case, the color appears more brown and blackish in the main lesion, but the yellow color can still be appreciated in the small outlying papules. The nodule near the center represents the malignant change. Because neoplasms eventually occur in about one-third of patients with nevus sebaceus, it is considered advisable to arrange for the excision of all such lesions before puberty.
These very small papules are adenomas of intraepidermal eccrine ducts. Most commonly, syringomas develop on the eyelids of women during adolescence or early adult life. Figure 22-5 is a good example of the fine papules that occur on the lower eyelids. They have no malignant potential, but the lesions are usually multiple and therefore the cause of cosmetic concern. Syringomas of this type may be delicately removed by electrodesiccation and curettage. Figure 22-6 is a representation of even smaller lesions, this time on the upper part of the chest. Rarely, a child or adolescent will develop successive crops of syringomas on the skin of the anterior neck, antecubital fossa, axilla, and groin. This condition, termed eruptive syringoma, is sometimes inherited in autosomal dominant fashion. Syringomas may be seen with increased frequency in patients with Down syndrome.
This benign eccrine sweat gland tumor occurs as a solitary lesion in most cases. Most commonly, the growth appears as a small intraepidermal nodule. Ulceration ...