Chapter 159. Sebaceous Hyperplasia

A 65-year-old man noted a new growth on his face for 1 year (Figure 159-1). On close examination, the growth was pearly with a few telangiectasias. The doughnut shape and presence of sebaceous hyperplasia scattered on other areas of the face were reassuring that this may be nothing but benign sebaceous hyperplasia. To reassure the patient and to remove the lesion a shave biopsy was performed to rule out basal cell carcinoma (BCC). The patient was relieved when the pathology result was in fact sebaceous hyperplasia. Additionally, he was pleased with the cosmetic result.

Sebaceous hyperplasia (SH) is a common, benign condition of sebaceous glands consisting of multiple asymptomatic small yellow papules with a central depression. The sebaceous lobules of SH are greater in number and higher in the dermis than normal sebaceous glands and only 1 gland appears enlarged.1 Consequently, the term hyperplasia appears to be a misnomer, and SH is more accurately classified as a hamartoma (disorganized overgrowth of tissue normally found at that site).1

• SH occurs in approximately 1% to 26% of the adult population; the latter number is from a population study of hospitalized patients with a mean age of 82 years.1
• The prevalence of SH is increased in those with immunosuppression by 10-fold to 30-fold1; for example, 10% to 16% of patients receiving long-term immunosuppression with cyclosporine in one study had SH.2
• SH has also been reported in infants where they are considered physiologic,3 and in young adults who may have a family history of SH.1
• SH has been reported overlying other skin lesions including neurofibromas, melanocytic nevi, verruca vulgaris, and skin tags.1
• Rare forms of SH include giant linear (up to 5 cm in diameter) and functional familial (also called premature or diffuse SH); the latter occurring typically around puberty as thick plaque-like lesions with pores resembling an orange peel.1

• Sebaceous glands, a component of the pilosebaceous unit, are found throughout the skin, everywhere that hair is found. The greatest number is found on the face, chest, back, and the upper outer arms.
• The glands are composed of acini attached to a common excretory duct. In some areas, these ducts open directly to the epithelial surface, including the lips and buccal mucosa (i.e., Fordyce spots), glans penis or clitoris (i.e., Tyson glands), female areolae (i.e., Montgomery glands), and eyelids (i.e., meibomian glands).1
• Sebaceous glands are highly androgen sensitive and become increasingly active at puberty and reach their maximum by the third decade of life.
• The cells that form the sebaceous gland, sebocytes, accumulate lipid material as they migrate from the basal layer of the gland to the central duct where they release the lipid content as sebum. In younger individuals, turnover of sebocytes occurs approximately every month.
• With aging, the turnover of sebocytes slows; this results in crowding of primitive sebocytes within the sebaceous gland, causing a benign hamartomatous enlargement called SH.1
• Genetic factors include overexpression of the aging-associated gene Smad7 and parathormone-related protein.4
• There is no known potential for malignant transformation, but SH may be associated with nonmelanoma skin cancer in patients following organ transplantation.

• Associated with Muir-Torre syndrome (concurrent or sequential development of a sebaceous neoplasm and an internal malignancy or multiple keratoacanthomas, an internal malignancy, and a family history of Muir-Torre syndrome).
• Immunosuppression
• Ultraviolet radiation4

Clinical Features

• Lesions appear as yellowish, soft, small papules ranging in size from 2 to 9 mm (Figures 159-1, 159-2, and 159-3).1
• Surface varies from smooth to slightly verrucous.
• Lesions can be single or multiple.
• Increasing number of lesions with aging; higher frequencies after 40 to 50 years of age.1
• In functional familial SH, lesions may appear thick and plaque-like, with pores that resemble an orange peel; the skin in these patients is quite oily.1
• Lesions may become red and irritated and bleed after scratching, shaving, or other trauma and may be associated with telangiectasias.
• Central umbilication (doughnut shape) from which a small amount of sebum can sometimes be expressed (Figures 159-1, 159-2, and 159-3).

Typical Distribution

• Most commonly located on the face, particularly the nose, cheeks, and forehead. May also be found on the chest, areola, mouth, and, rarely, the vulva.1,5

Imaging

• Dermoscopy may aid in distinguishing between nodular BCC and SH; a vascular pattern with orderly winding, scarcely branching vessels extending toward the center of the lesion is specific for hyperplastic sebaceous glands.6

Biopsy

• Not usually necessary unless concerned about BCC.

• Nodular BCC—These lesions can appear as waxy papules with a central depression that may ulcerate, most commonly located on the head, neck, and upper back. They may have a pearly appearance, surface telangiectases, and bleed easily (Figures 159-4 and 159-5).
• Fibrous papule of the face is a benign, firm, papule of 1 to 5 mm that is usually dome-shaped and indurated with a shiny, skin-colored appearance. Most lesions are located on the nose and, less commonly, on the cheeks, chin, neck, and, rarely, the lip or forehead.
• Milia are common, benign, keratin-filled cysts (histologically identical to epidermoid cysts) that occur in persons of all ages. They are 1 to 2 mm, superficial, uniform, pearly white to yellowish, domed lesions usually occurring on the face (Figure 159-6).
• Molluscum contagiosum are firm, smooth, usually 2- to 6-mm umbilicated papules that may be present in groups or widely disseminated on the skin and mucosal surfaces. The lesions can be flesh colored, white, translucent, or even yellow in color. Lesions generally are self-limited but can persist for several years (Chapter 130, Molluscum Contagiosum).
• Syringoma is a benign adnexal neoplasm formed by well-differentiated ductal elements. They are 1- to 3-mm skin-colored or yellowish dermal papules with a rounded or flat top arranged in clusters, and symmetrically distributed primarily on the upper parts of the cheeks and lower eyelids (Figure 159-6).
• Xanthomas are deposits of lipid in the skin or subcutaneous tissue that manifest clinically as yellowish papules, nodules, or tumors. They are usually a consequence of primary or secondary hyperlipidemia and occur in patients older than age 50 years. The lesions are soft, velvety, yellow, flat, polygonal papules that are asymptomatic and usually bilateral and symmetric (Chapter 223, Hyperlipidemia).

SH does not require treatment but can be removed for cosmetic purposes or if it becomes irritated. Evidence supporting treatment comes primarily from case series.

• Options for removal include cryotherapy, electrodesiccation, topical chemical treatments (e.g., with bichloracetic acid or trichloroacetic acid), oral isotretinoin (10 to 40 mg a day for 2 to 6 weeks), laser treatment (e.g., with argon, carbon dioxide, or pulsed-dye laser), photodynamic therapy (i.e., combined use of 5-aminolevulinic acid and visible light),7 shave excision, and punch excision.1 Complications of these therapies include atrophic scarring and changes in pigmentation.

No follow-up is needed.

Patient Resources

• http://www.skinsight.com/adult/sebaceousHyperplasia.htm.

Provider Resources

• http://emedicine.medscape.com/article/1059368-overview.