What is a Jadassohn’s sebaceous nevus?
It is a hamartoma of sebaceous glands. A hamartoma is a malformation composed of a benign and mixed proliferation of mature cells that are arranged in a disorderly and excessive way, so it would correspond to the area where it appears.
What does a sebaceous nevus look like?
It usually appears from birth or in childhood as an orange-yellowish alopecic (hairless) papule or plaque on the scalp. It can also be located in other areas of the head or neck. In general, it is a solitary lesion, although several elements can be grouped together. It has a rounded or linear morphology.
Is it very common?
It is estimated that it affects 0.3% of the world’s population, whether female or male.
How important is a sebaceous nevus for health?
It is a benign proliferation that can occasionally cause other benign tumors (e.g., trichoblasttoma or papiliferous syringocystadenoma) and exceptionally some other malignant tumors (the most common, basal cell carcinoma). The vast majority of cases have no relevance other than aesthetics.
In other cases, sebaceous nevus is one more manifestation of more complex syndromes that include intracranial masses, epilepsy, mental retardation, skeletal anomalies, eye lesions and renal hamartomas.
How is a sebaceous nevus diagnosed?
Observation and dermoscopy are usually sufficient to reach the diagnosis. When in doubt, skin biopsy is feten.
How is Jadahsson’s sebaceous nevus treated?
The only way is its complete removal by surgery or CO2 laser. According to a large study by Barkham, the prophylactic removal of a sebaceous nevus is not always mandatory (especially in childhood), but when there is a suspected risk of degeneration or when the aesthetic aspect is an inconvenience. In general, it is advised that treatment should not be considered until adolescence , since the risk of malignant degeneration during childhood is negligible.
Surgery allows the complete removal of the lesion and its histological study, although the procedure usually leaves a scar. On the other hand, the CO2 laser allows a much more cosmetic removal but does not allow the histological study of the piece, since the lesion is destroyed. Another therapeutic option is photodynamic therapy, which has the same drawbacks and virtues as the CO2 laser.
REFERENCES
· Barkham MC, White N, Brundler MA, Richard B, Moss C. Should naevus sebaceus be excised prophylactically? A clinical audit. J Plast Reconstr Aesthet Surg. 2007; 60(11):1269-70.
· In SI, Lee JY, Kim YC. Topical photodynamic therapy for nevus sebaceous on the face. Eur J Dermatol. 2010 Sep-Oct; 20(5):590-2.