Basal cell carcinoma (BASALIOMA)
A slow-growing, invasive, but usually non-metastasizing neoplasm recapitulating normal basal cells of the epidermis or hair follicles, most commonly arising in sun-damaged skin of the elderly and fair-skinned. Syn: basal cell epithelioma.
Alternative Names: Rodent ulcer; Skin cancer - basal cell; Cancer - skin - basal cell.
Basal cell carcinoma is a type of skin cancer. It is a malignant epithelial cell tumor that begins as a papule (a small, circumscribed, solid elevation of the skin) and enlarges peripherally, developing into a crater that erodes, crusts, and bleeds. Metastasis is rare, but local invasion destroys underlying and adjacent tissue. In 90 percent of all cases, the lesion is seen between the hairline and the upper lip.
Basal cell carcinoma (BCC) is the most common and least lethal form of all cancers. In the United States, basal cell cancer accounts for 90 percent of all skin cancers in the southern states, and 47 percent in the northern states.
It occurs most frequently in people over 45 years of age, and almost twice as often in men as in women. The incidence is far more prevalent among Caucasians. It occurs less often in Asians and rarely among African-Americans. The risk of skin cancer is related to the amount of sun exposure and pigmentation in the skin. The longer the exposure to the sun and the lighter the skin, the greater the risk of skin cancer.
The most common type of basal cell carcinoma is nodular basal cell carcinoma, a flesh-colored (cream to pink), round or oval translucent nodule with overlying small blood vessels and a pearly-appearing rolled border.
The second type of BCC is the pigmented lesion. This is darker than the nodular type, appearing blue, brown or black. It may be similar in appearance to the very aggressive malignant melanoma tumor. It is very important to distinguish between malignant melanomas and pigmented BCC.
A third type of BCC is the superficial type, which appears as red, and often scaly, localized plaque. It is frequently confused with psoriasis or eczema.
The tumors usually begin as small, shiny, firm, raised growths (papules) that enlarge very slowly, sometimes so slowly that they go unnoticed as new growths. However, the growth rate varies greatly from tumor to tumor, with some growing as much as inch (about 1 centimeter) in a year.
Basal cell carcinomas can vary greatly in their appearance. Some are raised bumps that may break open and form scabs in the center. Some are flat pale or red patches that look somewhat like scars. The border of the cancer is sometimes thickened and pearly white. The cancer may alternately bleed and form a scab and heal, leading a person to falsely think that it is a sore rather than a cancer.
Basal cell carcinomas rarely spread (metastasize) to distant parts of the body. Instead, they invade and slowly destroy surrounding tissues. When basal cell carcinomas grow near the eye, mouth, bone, or brain, the consequences of invasion can be serious and can lead to death. Yet, for most people, the tumors simply grow slowly into the skin.
According to the U.S. National Institutes of Health, ultraviolet (UV) radiation from the sun is the main cause of skin cancer. Artificial sources of UV radiation, such as sunlamps and tanning booths, can also cause skin cancer. The risk of developing skin cancer is also affected by where a person lives. People who live in areas that receive high levels of UV radiation from the sun are more likely to develop skin cancer. In the United States, for example, skin cancer is more common in Texas than it is in Minnesota, where the sun is not as strong. Worldwide, the highest rates of skin cancer are found in South Africa and Australia, which are areas that receive high amounts of UV radiation. In addition, skin cancer is related to lifetime exposure to UV radiation. Most skin cancers appear after age 50, but the sun's damaging effects begin at an early age. Therefore, protection should start in childhood in order to prevent skin cancer later in life.
Basal cell carcinoma may look only slightly different than normal skin. The cancer may appear as skin bump or growth that is:
Pearly or waxy.
- White or light pink.
- Flesh-colored or brown, in some cases the skin may be just slightly raised or even flat.
You may have:
A skin sore that bleeds easily.
Causes and Risk factors:
- A sore that does not heal.
- Oozing or crusting spots in a sore.
- Appearance of a scar-like sore without having injured the area.
- Irregular blood vessels in or around the spot.
- A sore with a depressed (sunken) area in the middle.
Environmental Factors: As with many other diseases, basal cell carcinomas seem to result from a combination of genetic and environmental factors. Most of the environmental damage to skin cells comes from exposure to UV radiation from sunlight. Although some studies show that the greatest harm occurs during childhood and adolescence, UV damage also appears to be cumulative, so the more time you spend in the sun, the greater your chance of developing skin cancer. Your risk increases even more if most of your outdoor exposure takes place in locales or at times of day when the sun is strongest.
Chemical Toxins: Arsenic, a toxic metal that's found widely in the environment, is a well-known cause of basal cell carcinoma and other cancers. Though arsenic contaminates the soil, air and groundwater, most people get their greatest exposure in food, especially chicken, beef and fish, and in wine grapes sprayed with arsenic-containing toxins. The U.S. Department of Health and Human Services estimates that the average American ingests 11 to 14 milligrams of arsenic every day. Farmers, refinery workers, and people who drink contaminated well water or live near smelting plants are likely to ingest much higher levels.
Immunosuppressant Drugs: People who take medications to prevent organ rejection after transplant surgery have a greatly increased risk of basal cell carcinoma, though symptoms may not appear for years after the operation.
Genetic factors: Several inherited disorders cause basal cell carcinoma or greatly increase your risk, including:
Nevoid basal cell carcinoma syndrome (Gorlin's syndrome): People with this rare genetic disorder have numerous basal cell carcinomas as well as pitting on their hands and feet, spine abnormalities, and cataracts.
Bazex's syndrome: This disorder is marked by numerous basal cell tumors on the face and by a lack of sweating and body hair.
Xeroderma pigmentosum: People with xeroderma pigmentosum, which causes an extreme sensitivity to sunlight, are at high risk of skin cancer because they have little or no ability to repair damage to the skin from ultraviolet light.
Some common risk factors for basal cell carcinoma include:
Chronic sun exposure mainly to UVB radiation but also UVA.
- A history of repeated sunburns or childhood exposure to the sun.
- A suppressed immune system.
- HIV disease.
- Fair skin and the propensity to freckle or burn rather than tan.
- Some rare risk factors for basal cell carcinoma include:
- Exposure to arsenic.
- A condition called granuloma inguinale.
- Scarred or previously damaged skin, especially radiation damage.
- Rare genetic diseases such as xeroderma pigmentosa, nevoid basal cell carcinoma syndrome, and albinism.
Doctors often can recognize a basal cell carcinoma simply by looking at it, but a biopsy is the standard procedure for confirming the diagnosis.
Doctors remove the cancer in the office by scraping and burning it with an electric needle (curettage and electrodesiccation) or by cutting it out. Also, certain chemotherapy drugs may be applied to the skin. A technique called Mohs microscopically controlled surgery may be required for some basal cell carcinomas that regrow or occur in certain areas, such as around the nose and eyes. Rarely, radiation treatment is used.
Treatment is nearly always successful, and basal cell carcinoma is rarely fatal. However, almost 25% of people with a history of basal cell carcinoma develop a new basal cell cancer within 5 years. Thus, anyone with one basal cell carcinoma should have a yearly skin examination.
Because basal cell carcinoma is often caused by sun exposure, people can help prevent this cancer by staying out of the sun and using protective clothing and sunscreen. In addition, any skin change that persists for more than a few weeks should be evaluated by a doctor.
Treatment varies depending on the size, depth, and location of the basal cell cancer. It will be removed using one of the following procedures:
Treating Basal Cell Carcinoma with Electrodessication and Curettage: Electrodessication and curettage involves destroying the tumor with an electrocautery device then scraping the area with a curette. Many times the diseased tissue can be differentiated from the normal tissue by the texture felt while scraping. This process is repeated several times to ensure complete removal of the tumor. This procedure is useful for small tumors less than 6 mm because it tends to leave a scar.
Treating Basal Cell Carcinoma with Simple Excision: This procedure involves surgical excision of the lesion including a margin of normal skin. This method is preferred for larger lesions (>2cm) on the cheek, forehead, trunk, and legs. The advantage of this treatment is that it is quick and inexpensive. However, the difference between normal and cancerous tissue must be judged with the naked eye.
Treating Basal Cell Carcinoma with Mohs' Micrographic Surgery: Mohs' micrographic surgery is a special type skin surgery that must be performed by an experienced Mohs' surgeon. It involves excision of the tumor and immediate examination of the tissue under the microscope to determine margins. If any residual tumor is left, it can be mapped out and excised immediately. The process of excision and examination of margins may have to be repeated several times. The advantage of this technique is that it is usually definitive and has been reported to have a lower recurrence rate than other treatment options. The disadvantage is the time and expense involved.
Treating Basal Cell Carcinoma with Radiation Therapy: This procedure involves a course of radiation therapy to the tumor area. It is used for some primary tumors in patients who are not fit for surgery or have inoperable tumors. It may also be used where tumors are difficult to excise or where it is important to preserve surrounding tissue such as the lip. Its use is declining.
Treating Basal Cell Carcinoma with Cryotherapy: Cryotherapy involves destroying the tissue by freezing it with liquid nitrogen. This may be effective for small, well-defined superficial tumors. It is also used effectively for the treatment of actinic keratosis, a premalignant condition. This procedure is inexpensive and time-efficient but can only be used in a small number of cases.
Carbon Dioxide Laser: This method is most frequently applied to the superficial type of basal cell carcinoma. It may be considered when a bleeding diathesis is present, since bleeding is unusual when this laser is used.
Topical fluorouracil (5-fu): This method may be helpful in the management of selected patients with superficial basal cell carcinomas. Careful and prolonged follow-up is required, since deep follicular portions of the tumor may escape treatment and result in future tumor recurrence.
Interferon Alpha: Several early studies have shown variable responses of basal cell carcinoma to intralesional interferon alpha. Further reports are awaited until this treatment may be recommended for routine clinical practice.
Photodynamic Therapy: Photodynamic therapy with photosensitizers may be effective treatment for patients with superficial epithelial skin tumors.
Medicine and medications:
5% 5-fluorouracil (Efudex) applied twice daily for 2-12 weeks of treatment can be effective in treating superficial basal cell carcinoma, with a reported cure rate as high as 93%.3 The use of 5-fluorouracil for other types of basal cell carcinoma is generally not recommended because it may not penetrate deeply enough into the dermis to eradicate all tumor cells. Irritation and crusting is common and expected; significant irritation and discomfort are not uncommon.
Imiquimod cream (Aldara) is FDA approved for the treatment of superficial basal cell carcinoma. Several studies have shown cure rates of up to 88% for superficial basal cell carcinoma. Smaller studies have shown similar cure rates for nodular basal cell carcinoma. Studies for other histologic types of basal cell carcinoma are currently underway. Treatment is usually initiated 3 times per week and advanced as tolerated to once daily and even twice daily if tolerated to maintain mild-to-moderate skin irritation. Patients can titrate the frequency of application to maintain low-moderate skin irritation. A 12-week course of treatment is often used, which does not need be contiguous.
DISCLAIMER: This information should not substitute for seeking responsible, professional medical care.