Basal Cell Epithelioma
Basal Cell Epithelioma (Carcinoma)
A slow growing, destructive skin tumor, basal cell epithelioma or carcinoma usually occurs in persons over age 40; it's more prevalent in blond, fair skinned males and is the most common malignant tumor affecting whites.
Prolonged sun exposure is the most common cause of basal cell epithelioma, but arsenic ingestion, radiation exposure, burns, immunosuppression and, rarely, vaccinations are other possible causes.
Although the pathogenesis of basal cell epithelioma is uncertain, some experts now hypothesize that it originates when, under certain conditions, undifferentiated basal cells become carcinomatous instead of differentiating into sweat glands, sebum, and hair.
Signs and symptoms
Three types of basal cell epithelioma occur:
- Noduloulcerative lesions occur most often on the face, particularly the forehead, eyelid margins, and nasolabial folds. In early stages, these lesions are small, smooth, pinkish, and translucent papules. Telangiectatic vessels cross the surface, and the lesions are occasionally pigmented. As the lesions enlarge, their centers become depressed and their borders become firm and elevated. Ulceration and local invasion eventually occur. These ulcerated tumors, known as "rodent ulcers," rarely metastasize; however, if untreated, they can spread to vital areas and become infected. If they invade large blood vessels, they can cause massive hemorrhage.
- Superficial basal cell epitheliomas are often numerous and commonly occur on the chest and back. They're oval or irregularly shaped, lightly pigmented plaques, with sharply defined, slightly elevated threadlike borders. Because of superficial erosion, these lesions appear scaly and have small, atrophic areas in the center that resemble psoriasis or eczema. They're usually chronic and don't tend to invade other areas. Superficial basal cell epitheliomas are related to ingestion of or exposure to arsenic containing compounds.
- Sclerosing basal cell epitheliomas (morphealike epitheliomas) is the most difficult to diagnose, and is prone to recur after apparently adequate surgery. They look like a skin-coloured, rather waxy, thickened scar.
All types of basal cell epitheliomas are diagnosed by clinical appearance, an incisional or excisional biopsy, and histologic study.
Depending on the size, location, and depth of the lesion, treatment may include curettage and electrodesiccation, chemotherapy, surgical excision, irritation, cryotherapy, or chemosurgery.
- Curettage and electrodesiccation offer good cosmetic results for small lesions.
- Shave, curettage, & cautery (and other types of minor surgery). Many small, well defined nodular or superficial BCCs can be successfully removed by removing just the top layers of the skin. The wound usually heals within a few weeks without needing stitches.
- CLINICAL TIP Topical fluorouracil is often used for superficial lesions. This medication produces marked local irritation or inflammation in the Involved tissue but no systemic effects.
- Microscopically controlled surgical excision carefully removes recurrent lesions until a tumor-free plane is achieved. After removal of large lesions, "kill grafting may be required.
- Irradiation is used if the tumor location requires it and for elderly or debilitated patients who might not withstand surgery.
- Cryotherapy with liquid nitrogen freezes and kills the cells.
- Chemosurgery is often necessary for persistent or recurrent lesions. Chemosurgery consists of periodic applications of a fixative paste (such as zinc chloride) and subsequent removal of fixed pathologic tissue. Treatment continues until tumor removal is complete.
- Imiquimod cream . This is applied to superficial BCCs three to five times each week (Monday to Friday) for six to sixteen weeks. The imiquimod results in an inflammatory reaction, maximal at three weeks. Up to 85% of suitable BCCs disappear, with minimal scarring.
- People who have had a basal cell carcinoma should have a skin exam every six months to one year.
- Advise the patient to relieve local inflammation from topical fluorouracil with cool compresses or corticosteroid ointment.
- Sun exposure and sunbathing produce gradual skin damage even if sunburn is avoided. Ten to forty years can pass between the time of sun exposure and the development of skin cancer.
- Instruct the patient to eat frequent small meals that are high in protein. Suggest eggnog, pureed foods, or liquid protein supplements if the lesion has invaded the oral cavity and caused eating problems.