What Is Sebaceous Adenoma?
Sebaceous adenoma is a rare benign tumor that derives from the sebaceous glands. Clinically it appears as a small firm nodule on the skin that looks similar to basal cell carcinoma. The most common sites of sebaceous adenoma include the scalp, face, belly, back, or chest. It most commonly affects elderly patients with a mean age of 60. Multiple sebaceous adenomas are referred to as sebaceous hyperplasia. They are mostly harmless and do not require any treatment, but they may be treated if it bothers the patient's look.
What Causes Sebaceous Adenoma?
- Hormonal changes in the body most commonly cause sebaceous adenoma and sebaceous hyperplasia. For example, the androgen (group of sex hormones) levels decrease with age, leading to lower turnover of sebocytes (primary cell type in sebaceous glands). Therefore it stimulates the production of more sebocytes within the sebaceous glands leading to the formation of sebaceous adenomas.
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Maternal hormones circulating in newborns enlarge the sebaceous glands, resulting in the formation of sebaceous adenomas or hyperplasias. The sebaceous adenoma in newborns is temporary; within months, they shrink and disappear.
Who Are More Likely to Get Sebaceous Adenomas or Sebaceous Hyperplasia?
Sebaceous adenomas or sebaceous hyperplasia can occur on anyone, but it most likely appears on;
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Newborn babies.
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Middle-aged people.
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Immunosuppressed patients (especially patients who received immunosuppressants for getting organ transplantation).
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Persons affected with genetic syndromes such as Muir-Torre syndrome.
What Are the Clinical Features of Sebaceous Adenomas?
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Clinically sebaceous adenoma looks like a well-circumscribed small yellowish, tan, pink, or skin-colored nodule with size ranging from two to nine millimeters. It often exhibits a speckled, smooth surface with central crustation or umbilication (a central navel-like depression).
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The lesions may be either solitary or multiple (sebaceous hyperplasia). It is usually asymptomatic, but sometimes the lesions tend to ulcerate and cause bleeding and pain.
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Nearly 70% of lesions occur on the head and face, most commonly affecting the nose and cheeks. The other common sites include the neck, trunk, and extremities.
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Clinically it looks similar to basal cell carcinoma (skin cancer that develops in the basal cells).
How Is Sebaceous Adenoma Diagnosed?
- Doctors generally undergo a complete skin examination to diagnose sebaceous adenoma. The doctor might use a dermoscope to inspect skin lesions during skin examination. The dermoscope is a non-invasive diagnostic tool consisting of a magnifier that helps visualize the subsurface skin lesions.
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The doctors suggest a skin biopsy to distinguish sebaceous adenoma from basal cell carcinoma. In a skin biopsy, a small skin sample is removed and sent to the laboratory for pathological examination. The histological findings obtained from the skin biopsy help the doctor distinguish between benign and malignant skin lesions.
There is no need for any specific diagnostic tests other than those for diagnosing sebaceous adenoma.
How Is Sebaceous Adenoma Treated?
Sebaceous adenoma and sebaceous hyperplasia are asymptomatic and usually do not require any treatment. But sometimes, the lesions tend to ulcerate and cause bleeding, pain, discomfort, and itchiness. Therefore, treatment for sebaceous adenoma may be needed if the lesions are symptomatic or if the patient desires it.
Medications for Sebaceous Adenoma:
The medications used to treat sebaceous adenoma include:
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Isotretinoin: The doctors suggest Isotretinoin pills or capsules for treating sebaceous adenoma. It helps reduce the size of sebaceous glands, and it has proven to be effective in clearing the lesions completely after six weeks of treatment. However, the lesions do recur upon discontinuation of the drug.
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Trichloroacetic Acid: Topic Trichloroacetic acetic acid is used to treat sebaceous adenoma and sebaceous hyperplasia. A concentration of 70% topical trichloroacetic acid helps treat sebaceous hyperplasia. It does not cause any discomfort usually, but sometimes it may lead to a burning sensation for a short time. Chemical cauterization and 70% trichloroacetic acid are more effective in treating sebaceous hyperplasia.
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Anti-androgen Drugs: Increased testosterone levels seem to be a possible cause of sebaceous adenoma and sebaceous hyperplasia. Therefore doctors may suggest anti-androgen medications to reduce testosterone levels and treat sebaceous adenoma. However, it is prescribed only for women.
Some of the other treatment options that help remove sebaceous adenoma include;
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Electrocauterization: Electrocauterization is a surgical procedure that helps remove the sebaceous adenoma lesions using heat. In electrocauterization, an electric current is passed through a metal electrode from which heat is generated. The heated electrode then removes the lesions from the skin by burning it with little or no scarring. However, it may also lead to skin discoloration in the affected area.
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Cryotherapy: Cryotherapy is a dermatologic procedure used to remove the sebaceous adenoma lesions. In the cryotherapy procedure, a cryoprobe (a blunt chilled instrument) cooled with substances such as compressed argon gas, liquid nitrogen gas, or liquid nitrous oxide is used to freeze and remove the abnormal tissues.
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Laser Therapy: Laser therapies like argon and carbon dioxide lasers help remove the sebaceous adenoma lesions. It is a non-invasive, safe treatment procedure that requires no recovery time.
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Photodynamic Therapy: Photodynamic therapy is a minimally invasive therapeutic procedure that uses photosensitizing agents (chemical substances that cause chemical changes inside cells by absorbing light) along with light energy to destroy abnormal cells or tissue.
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Surgical Excision: Surgical excision of sebaceous adenomas helps obliterate the lesion and prevent its recurrence. However, doctors usually consider it the last treatment since it results in permanent scarring over the affected area.
How Can Sebaceous Adenoma Be Prevented?
Sebaceous adenoma cannot be prevented from forming, but some skin medications may help reduce the risk of developing it. It includes;
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Niacinamide: Niacinamide (vitamin B3) helps control excess sebum production and repairs the skin's protective barrier. It can be either used in the form of serums or tablets.
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Salicylic Acid: Treating sebaceous adenoma or sebaceous hyperplasia with salicylic acid is highly effective. It helps prevent clogging of sebaceous glands. It can be incorporated into daily skincare routine through face wash, serums, cleansers, and topical lotions.
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Retinol: Retinol (vitamin A) used in the form of a serum or topical cream can help prevent the clogging of sebaceous glands.
Which Syndrome Is Associated With Sebaceous Adenoma?
The syndrome associated with sebaceous adenoma is Muir-Torre syndrome. Muir-Torre syndrome is a genetic disorder associated with malignancies of the internal organs (cancers of the colon and genitourinary tract) and sebaceous tumors (sebaceous adenoma or epithelioma, or keratoacanthoma). It occurs due to mutations in MLH1 and MSH2 genes.
Immunohistochemistry is the most commonly used diagnostic measure for Muir-Torre syndrome since it is frequently associated with sebaceous neoplasms. Therefore, the treatment options mainly depend on visceral malignancy and sebaceous neoplasm associated with Muir-Torre syndrome.
Conclusion:
Sebaceous adenomas are usually asymptomatic and do not require any treatment. However, they may be symptomatic in some instances leading to pain, bleeding, and discomfort. Therefore, the doctors may suggest treatment only if it becomes symptomatic or bothers the patient's look. Doctors recommend skin medications like Isotretinoin and Trichloroacetic acid for treating sebaceous adenoma, which helps in reducing the size of the lesion and inhibit the proliferation of sebocytes. If the patient desires complete removal of the lesion, the doctor may suggest treatments like surgical excision, laser therapy, and electrocauterization.
