A nevus sebaceus is a solitary, well-circumscribed, yellow-orange
hairless plaque located on the face or scalp that is a hamartoma
of follicular, sebaceous, and apocrine origin.
Synonyms Nevus sebaceus of Jadassohn,
Age Usually present near birth.
May appear in childhood or adulthood.
Genetics Usually sporadic, rare
familial forms reported.
A nevus sebaceus is typically present near birth and has two
stages: prepubertal (infantile phase, see Fig. 10-1A) and pubertal
(adolescent phase, see Fig. 10-1B).
Nevus sebaceus in an infant
A. Slightly raised subtle findings of a nevus sebaceus in a
newborn. Nevus sebaceus in a child B. More
verrucous appearance of a nevus sebaceus on the scalp of an adolescent.
Type Hairless plaque surface may
be velvetlike, verrucous, or papillomatous.
Color Yellow, yellow-brown, orange,
Size Few millimeters to several
Shape Round, oval, or linear.
Distribution Head and neck.
Arrangement Solitary, rarely, multiple
lesions have been reported.
Typically there are no systemic symptoms. In the scalp, the lesion
remains hairless. Rarely, extensive lesions can be associated with
ocular, CNS, or skeletal abnormalities.
The differential diagnosis includes other appendageal tumors;
smaller lesions can resemble warts.
Dermatopathology Infancy: numerous
immature sebaceus glands and cords or buds of undifferentiated hair
follicles. Adult: papillomatous hyperplasia of the epidermis with
hyperkeratosis and hypergranulosis. There are also typically ectopic
apocrine glands located deep in the dermis.
Nevus sebaceus tend to grow slowly and become thicker and more
papillomatous with age. Approximately 10% may have neoplastic
changes that manifest as nodules or ulcers within the lesion: trichoblastoma,
trichilemmoma, syringocystadenoma papilliferum (Fig. 10-2) are the
most common neoplasms. Other possible growths include sebaceous
adenoma, apocrine adenoma, poroma, basal cell carcinoma, and squamous
Nevus sebaceus in an adult Central
ulceration and crusting in a postpubertal nevus sebaceus. Skin biopsy
revealed neoplastic changes suggestive of syringocystadenoma papilliferum.
Nevus sebaceus lesions before puberty can be observed regularly
for any signs or symptoms of neoplastic change. And after puberty,
although there is an increased risk of neoplasms such as syringocystadenoma