Nevus Sebaceous

Nevus sebaceous is also known as nevus sebaceous of Jadassohn and organoid nevus.

CLINICAL FEATURES

Nevus sebaceous presents as a linear, hairless, yellow, waxy, and verrucous plaque . It can be flat at birth, becoming plaque-like under the hormonal influences of puberty. These nevi are common in the scalp, but there are reports of lesions on the face, chest, and in oral mucosa. Tumors can arise within nevus sebaceous. The most common benign tumors are syringocystadenoma papilliferum and trichoblastoma. Other benign tumors reported to arise in a nevus sebaceous are the leiomyoma, syringoma, spiradenoma, hidradenoma, and keratoacanthoma. It was once believed that individuals with this tumor were at increased risk of basal cell carcinomas, but a retrospective review of 596 cases by Cribier et al. revealed that most lesions initially diagnosed as basal cell carcinoma were actually trichoblastomas. A second retrospective study of 757 tumors confirmed this finding. This does not exclude the possibility of the development of basal cell carcinoma in these lesions. Rarely, malignant tumors such as apocrine carcinoma, squamous cell carcinoma, and malignant eccrine poromas may arise within nevus sebaceous.

Nevus sebaceous syndrome is the very rare association of an extensive, congenital nevus sebaceous with ocular abnormalities and cerebral defects such as mental retardation or seizures. This syndrome is also known as Schimmelpenning-Feuerstein-Mims syndrome or organoid nevus syndrome.

PATHOLOGY

Immature sebaceous glands located high in the dermis and malformed pilosebaceous units are features of nevus sebaceous . Vellus hairs are more common than terminal hairs in these lesions. Epidermal acanthosis, hyperkeratosis, and pseudoepitheliomatous hyperplasia can also be seen.

DIFFERENTIAL DIAGNOSIS

Epidermal nevi, aplasia cutis, and congenital triangular alopecia may be clinically similar to nevus sebaceous but biopsy can easily distinguish between these entities.

TREATMENT

Excision of nevus sebaceous was common when these lesions were thought to carry an increased risk of basal cell carcinoma. Rapidly growing papules or nodules demand pathologic evaluation to evaluate for rare malignancies, but excision should be considered on a case-by-case manner.