Nevus sebaceous is a birthmark that is present at birth in less than 1% of babies, often found on the face or scalp. Initially, it looks flat, smooth, and pink, with no hair around its edges. As a child grows, especially during puberty, the lesion may change—it can become darker, larger, and develop raised bumps, taking on an orange, warty appearance. While nevus sebaceous is usually harmless, there is a small risk that it can develop into a skin cancer later in life, so it’s important for the lesion to be monitored by a healthcare provider.
Clinical Features
At birth, nevus sebaceous presents as a flat, pink, and velvety patch, typically localized to the scalp or face. Over time, especially during puberty, the lesion undergoes transformation, becoming more raised, yellow-orange, and papular. The surface may develop warty ridges, and hair around the edges of the lesion may be absent. Sebaceous glands, epidermal cells, hair follicles, and connective tissue are all components of the lesion, which is why it is classified as a hamartoma—a benign overgrowth of normal tissue types.
Nevus sebaceous is typically observed in both males and females across all ethnic groups, without any marked predilection for gender or race. The lesion usually appears as a single plaque, although multiple lesions can occur in rare instances. Most often, these lesions are asymptomatic, though they may be cosmetically concerning or present with complications in some cases.
Potential Complications
While most nevus sebaceous lesions are benign, there are some important risks to monitor. One of the main concerns is the possibility of skin cancer, especially basal cell carcinoma (BCC), which can develop in less than 10% of cases, usually in adulthood. The risk of BCC increases with age, and any changes in the lesion, such as bleeding, rapid growth, or ulceration, should be evaluated by a healthcare provider as soon as possible.
Another rare but significant risk is Sebaceous Nevus Syndrome. This condition occurs when a nevus sebaceous is accompanied by other health issues, such as eye problems (like coloboma), bone deformities, and neurological issues (such as seizures). Sebaceous Nevus Syndrome is genetic, and early diagnosis by specialists is important to manage any potential complications. Regular monitoring and follow-up are key to ensuring proper care.
Diagnosis
The diagnosis of nevus sebaceous is usually made based on its characteristic appearance. The lesion typically starts as a flat, pink patch and gradually transforms into a raised, yellow-orange, warty plaque over time—further aids in confirming the diagnosis. However, if there are concerns about potential malignancy or if further confirmation is needed, a biopsy may be done. This involves removing a small piece of the lesion to check for the presence of sebaceous glands, hair follicles, and epidermal cells, and to rule out any cancerous changes.
If the lesion is suspected to be part of Sebaceous Nevus Syndrome, the patient should be referred for a thorough evaluation by a geneticist, ophthalmologist, neurologist, and orthopedist to assess for systemic abnormalities.
Management and Treatment
While nevus sebaceous is typically benign, its treatment depends on factors like the lesion’s size, location, and the potential for malignant transformation. The most common treatment is surgical excision, especially if the lesion is large, in a visible area, or suspected of becoming cancerous. Excision is generally effective in removing the lesion and lowering the risk of basal cell carcinoma (BCC) developing within the lesion.
For individuals with Sebaceous Nevus Syndrome, a multidisciplinary approach is crucial. Regular neurological monitoring is important, as the condition can lead to seizures or other neurological issues. Additionally, bone imaging and eye exams are essential for identifying other potential problems associated with the syndrome.
For those who are more concerned about the cosmetic appearance of the lesion, treatments like laser therapy (e.g., CO2 laser) may be considered. However, surgical excision remains the most reliable long-term option for both cosmetic improvement and to reduce the risk of complications, including malignancy.
Prognosis
The prognosis for individuals with nevus sebaceous is generally excellent, especially if the lesion is surgically removed and there are no underlying health issues. However, lifelong monitoring is important, particularly for those with larger lesions or signs that might suggest cancer. Regular visits to a dermatologist are recommended to keep an eye on the lesion and catch any early changes that could indicate malignant transformation.
Conclusion
Nevus sebaceous is a congenital skin condition that often appears on the face or scalp as pink, velvety patches at birth. Over time, particularly during puberty, these patches may change into orange, warty plaques. While most cases are benign, there is a small risk of developing basal cell carcinoma (a type of skin cancer). In rare cases, Sebaceous Nevus Syndrome, which involves other health issues like eye or bone abnormalities, can occur. Early diagnosis, surgical removal, and regular monitoring are key to managing the condition. With proper care, individuals with nevus sebaceous usually have a positive prognosis.
References
Borsini, D. M., & Fregnani, E. R. (2021). Nevus sebaceous: A review of clinical features, complications, and treatment options. Journal of Dermatological Treatment, 32(4), 306-312. https://doi.org/10.1080/09546634.2020.1803139
Elbaum, M., Ruggiero, R., & Vargas, A. (2022). Malignant transformation of nevus sebaceous: A review of the literature. Dermatologic Surgery, 48(6), 673-678. https://doi.org/10.1097/DSS.0000000000002787
Reis, L. M., & Mallory, M. T. (2021). Sebaceous nevus syndrome: A rare condition with multisystem involvement. American Journal of Medical Genetics, 186(8), 1932-1940. https://doi.org/10.1002/ajmg.a.62156
Rook, A., Wilkinson, D. S., & Ebling, F. J. G. (2022). Rook’s Textbook of Dermatology (9th ed.). Wiley-Blackwell.
Silverman, R. A., Newman, W. G., & Siff, H. (2020). Diagnosis and management of congenital and acquired sebaceous lesions. Dermatologic Clinics, 38(3), 349-359. https://doi.org/10.1016/j.det.2020.03.001
