Joseph Jadassohn first described this nevus in 1895. It is also referred to as organoid nevus. It is considered a congenital nevus (mole) presenting as a yellow-orange plaque with sharp margins. They are often linear and most often solitary.
The scalp is the most common location (50%), but other areas of the head and neck (45%) are also very common regions. The trunk is involved in less than 5% of cases. It is interesting that I often have older male patients present for evaluation of a newly discovered Nevus Sebaceus due to recession of the hair line. Many of the lesions are alopecic…that is…hair does not grow within the lesion (see photographs below).
Nevus Sebaceus (correct spelling by the way) are hamartomas of the pilosebaceous follicular unit…resulting in an overgrowth of sebaceous glands, hair follicles, apocrine glands and connective tissue. Although generally a benign congenital mole, rarely there may be adnexal neoplasms that develop:
- Trichoblastoma and syringocystadenoma papilliferum occur in about 5%
- Basal cell carcinoma occur in less than 1%
- Trichilemmoma (reported)
- Infundibular cyst (reported)
- Squamous cell carcinoma (reported)
- Sebaceous carcinoma (reported)
Nevus Sebaceus (Nevus Sebaceus Syndrome) can be associated with multiple internal abnormalities…thus it is categorized within the epidermal nevus syndrome disorders. Although I have identified and treated many Nevus Sebaceus I have yet to discover a patient with this syndrome…which is a good thing…but it is very rare.
TREATMENT: Although the risk of developing a malignancy exists, it is very small, and virtually always occurs after adolescence. For this reason I recommend observation until adulthood. Cosmetic considerations should be considered and observation is an option due to the relatively benign nature of the tumors. This Blog is for educational purposes only and is not meant to replace an office visit, and if you believe you may have a Nevus Sebaceus I strongly encourage you to see a Dermatologist to confirm the diagnosis. To read more about Nevus Sebaceus of Jadassohn click HERE and HERE. To read about Basal Cell Carcinoma click HERE.