Benign Tumors of the Skin
Cysts of the skin are epithelium-lined cavities that contain fluid or solid material. Epidermal cysts (ie, epidermoid cysts) occur frequently and may be described as slow-growing, firm, elevated tumors found most frequently on the face, neck, upper chest, and back. Removal of the cysts provides a cure.
Pilar cysts (ie, trichilemmal cysts), formerly called sebaceous cysts, are most frequently found on the scalp. They originate from the middle portion of the hair follicle and from the cells of the outer hair root sheath. The treatment is surgical removal.
Seborrheic keratoses are benign, wartlike lesions of various sizes and colors, ranging from light tan to black. They are usually lo-cated on the face, shoulders, chest, and back and are the most common skin tumors seen in middle-aged and elderly people. They may be cosmetically unacceptable to the patient. A black keratosis may be erroneously diagnosed as malignant melanoma. The treatment is removal of the tumor tissue by excision, elec-trodesiccation and curettage, or application of carbon dioxide or liquid nitrogen. However, there is no harm in allowing these growths to remain, because there is no medical significance to their presence.
Actinic keratoses are premalignant skin lesions that develop in chronically sun-exposed areas of the body. They appear as rough, scaly patches with underlying erythema. A small percentage of these lesions gradually transform into cutaneous squamous cell carcinoma; they are usually removed by cryotherapy or shave excision.
Warts are common, benign skin tumors caused by infection with the human papillomavirus, which belongs to the DNA virus group. All age groups may be affected, but the condition occurs most frequently between ages 12 and 16 years. There are many types of warts.
As a rule, warts are asymptomatic, except when they occur on weight-bearing areas, such as the soles of the feet. They may be treated with locally applied laser therapy, liquid nitrogen, salicylic acid plasters, or electrodesiccation (ie, destruction of skin lesions by monopolar high-frequency electric current).
Warts occurring on the genitalia and perianal areas are known as condylomata acuminata. They may be transmitted sexually and are treated with liquid nitrogen, cryosurgery, electrosurgery, topically applied trichloracetic acid, and curettage. Condylomata that affect the uterine cervix predispose the pa-tient to cervical cancer.
Angiomas are benign vascular tumors that involve the skin and the subcutaneous tissues. They are present at birth and may occur as flat, violet-red patches (ie, port-wine angiomas) or as raised, bright-red, nodular lesions (ie, strawberry angiomas). The latter tend to involute spontaneously within the first few years of life, but port-wine angiomas usually persist indefinitely. Most patients use masking cosmetics (ie, Covermark or Dermablend) to cam-ouflage the lesion. The argon laser is being used on various an-giomas with some success. Treatment of strawberry angiomas is more successful if undertaken as soon after birth as possible (Odom et al., 2000).
Moles are common skin tumors of various sizes and shades, ranging from yellowish brown to black. They may be flat, mac-ular lesions or elevated papules or nodules that occasionally con tain hair. Most pigmented nevi are harmless lesions. However, in rare cases, malignant changes occur, and a melanoma devel-ops at the site of the nevus. Some authorities believe that all con-genital moles should be removed, because they may have a higher incidence of malignant change. However, depending on the quantity and location, this may be impractical. Nevi that show a change in color or size or become symptomatic (eg, itch) or develop irregular borders should be removed to determine if malignant changes have occurred. Moles that occur in unusual places should be examined carefully for any irregularity and for notching of the border and variation in color. Early melanomas may display some redness and irritation and areas of bluish pig-mentation where the pigment-containing cells have spread deeper into the skin. Late melanomas have areas of paler color, where pigment cells have stopped producing melanin. Nevi larger than 1 cm should be examined carefully. Excised nevi should be examined histologically.
Keloids are benign overgrowths of fibrous tissue at the site of a scar or trauma. They appear to be more common among dark-skinned people. Keloids are asymptomatic but may cause disfig-urement and cosmetic concern. The treatment, which is not always satisfactory, consists of surgical excision, intralesional cor-ticosteroid therapy, and radiation.
A dermatofibroma is a common, benign tumor of connective tis-sue that occurs predominantly on the extremities. It is a firm, dome-shaped papule or nodule that may be skin colored or pink-ish brown. Excisional biopsy is the recommended method of treatment.
Neurofibromatosis is a hereditary condition manifested by pig-mented patches (ie, cafĂ©-au-lait macules), axillary freckling, and cutaneous neurofibromas that vary in size. Developmental changes may occur in the nervous system, muscles, and bone. Malignant degeneration of the neurofibromas occurs in some patients.