Nevus sebaceous

Nevus_sebaceous.jpg

== Nevus Sebaceous ==

Nevus sebaceous, also known as nevus sebaceus of Jadassohn, is a congenital, benign hamartoma of the skin that typically presents at birth or in early childhood. It is characterized by an overgrowth of the sebaceous glands, hair follicles, and other epidermal structures.

Presentation

Nevus sebaceous usually appears as a solitary, well-demarcated, yellow-orange plaque. It is most commonly found on the scalp, but it can also occur on the face, neck, or other areas of the body. The lesion tends to be hairless and may become more pronounced and nodular during puberty due to hormonal changes.

Pathophysiology

The exact cause of nevus sebaceous is not fully understood, but it is believed to result from a post-zygotic mutation in the HRAS or KRAS genes. These mutations lead to the abnormal development of the epidermis, sebaceous glands, and other skin appendages.

Diagnosis

Diagnosis of nevus sebaceous is primarily clinical, based on the characteristic appearance of the lesion. A skin biopsy may be performed to confirm the diagnosis and to rule out other conditions. Histologically, nevus sebaceous shows hyperplasia of the sebaceous glands and other epidermal structures.

Complications

While nevus sebaceous is generally benign, there is a risk of secondary neoplasms developing within the lesion. These can include basal cell carcinoma, squamous cell carcinoma, and other benign or malignant tumors. Regular monitoring and, in some cases, prophylactic excision are recommended to manage this risk.

Treatment

Treatment options for nevus sebaceous include surgical excision, which is often recommended to prevent the development of secondary neoplasms. Other treatments, such as laser therapy, may be used to improve the cosmetic appearance of the lesion.

Prognosis

The prognosis for individuals with nevus sebaceous is generally good, especially if the lesion is monitored regularly and treated appropriately. The risk of malignant transformation is relatively low but warrants careful observation.

See Also

• Sebaceous gland
• Hamartoma
• Basal cell carcinoma
• Squamous cell carcinoma
• Skin biopsy