..........Aim of the squamous cell carcinoma section: After reviewing this chapter the reader should be more familiar with squamous cell carcinoma and skin growths such as the precancer, actinic keratosis, and Bowen's disease that may be related to squamous cell carcinoma. The different forms of squamous cell carcinoma, a potentially lethal yet usually very treatable skin cancer, will be discussed as well as various types of skin cancer surgery and other therapies currently in use to treat squamous cell carcinoma. Treatments including liquid nitrogen, Mohs Surgery, plastic surgery, reconstructive surgery and laser surgery are explained. Methods to detect squamous cell carcinoma including naked eye detection and skin biopsy methods will also be discussed in-depth. Suggestions and new findings regarding sunscreens and their relationships to squamous cell carcinoma are made.

.__Squamous-cell carcinoma (SCC) is a skin tumor or cancer likely derived from the keratinocytes (skin-surface cells) close to the surface of the skin. It is the second most- common skin cancer, ranking behind basal-cell carcinoma. Each year, 100,000 Americans are affected by SCC for the first time. Anyone with a substantial history of being in the sun may develop SCC (environmental factor). However, as with most cancers, genetics may play a role as well. People with blue, green or gray eyes are at highest risk, which underscores this genetic tendency. Possible precursors or precancers (growths that can develop into cancer) to SCC include actinic keratoses, actinic cheilitis (actinic keratosis on the pink or vermilion part of the lip) and leukoplakia (special white patches of the tongue or roof of the mouth). Preventing or treating precancers can reduce the chance of developing SCC, which is a potentially fatal condition.

......It is important to detect and treat SCC early. Usually, the earlier the detection, the easier and smaller the treatment. However, the larger the tumor has grown, the larger and more complicated the treatment needed. Even localized (confined to one area of the body) tumors that are not treated soon enough can result in the loss of an eye, ear or nose. Even though SCC from sun-damaged skin does not often metastasize (spread) internally, when it does, it is frequently fatal.

......SCC is graded depending on the degree to which the cells look unusual under the microscope. The less normal and natural the cells look, the more aggressively (badly) they usually behave. For example, poorly differentiated SCC, meaning not looking much like any normal tissue found in the skin, has a much greater tendency to spread unchecked and kill a patient. As with many skin cancers, spotting SCC early by knowing what to look for can save a life. In this section of the Web site, we describe SCC and its behavior. In a separate section, Treatment of BCC and SCC, we will explore treatment of SCC in a more lengthier discussion.

......Squamous-cell carcinoma may occur anywhere on the skin, but, importantly, SCC may also arise on the mucous membranes (inside mouth and nose, lips, throat, eyelids, lining of breathing tubes, anus, etc.). SCC of the skin most commonly arises in previously sun-damaged areas; however, it can arise in normal-appearing skin. Although SCC arising in sun-damaged skin metastasizes less than one percent of the time, one percent of the large numbers of SCC occurring in America results in many cases of fatal SCC arising on the skin. SCC may also arise in areas of chronic skin trauma or disease such as ulcers, sores, burn scars, chemical-exposure sites (arsenic or petroleum byproducts), radiation sites and sinus (deep, lined pocket) tracts. Although SCC of the skin usually remains confined to the epidermis (uppermost skin layer) for extended periods, many SCC's eventually will penetrate into the underlying tissues, if not treated properly. Overall, SCC of the skin metastasizes (travels through the lymph or blood stream to distant body sites) an estimated two to three percent of the time. The potential for metastasis is the potential to kill. It is critical to treat and recognize SCC early.

......To the naked eye, classical SCC often consists of a shallow ulcer (defect in the skin into the leather layer or dermis) surrounded by a thickened, usually reddened border. Partially or completely overlying the ulcer may be a crust (dried blood) or fibrin (whitish material derived from blood) or pus (white blood cells coming from the bloodstream trying to fight infection). Sometimes SCC can look like a wart or fungus. Interestingly, some skin SCC may be caused by particular, uncommon types of wart-virus. This is especially true of SCC in a woman's cervix, which is usually caused by wart-virus that is sexually spread.
...Squamous-cell carcinoma is a true and invading cancer of the very surface of the skin, called the epidermis. Under the microscope, SCC is composed of irregular globs of surface-derived skin cells growing into the deeper tissues. The invading balls of tumor are composed of differing amounts of relatively normal-appearing cells that tend to form the natural end-product of skin cells called keratin, the normal surface scale of cell body that we shed daily, and of atypical (unusual or strange) squamous cells. The more a cell can progress to its normal end product, the more we should consider a cell to be mature or benign. Atypical (unusual, tending toward cancer or cancer-like) cells tend to look and behave in an immature fashion and are usually less able to make the end-products of maturation. In SCC, that end-product would be the keratin that normal skin-surface epidermal cells make.

.......Cells are considered normal, mature and benign when they appear to reproduce or grow in a manner typical of healthy cells. Cells are considered abnormal, immature, atypical (not typical) and cancer-like when they appear to reproduce or grow individually or in patterns that are not typical of healthy cells. In SCC, the usually most abnormal types of cells produce less keratin than normal skin-surface epidermal cells.

......Usually, the greater the proportion and amount of atypical cells present, the more malignant (deadly, bad, trouble causing) the SCC. The dermatopathologist determines the degree of atypia in the tumor cells mostly by looking at the nuclei (plural of nucleus, the genetic center) of the cells. The nucleus of a cell is the genetic part that controls cell division and growth. Some SCC may behave less aggressively than BCC and other SCC may behave more aggressively than melanoma. (See Gray Zones.) Dermatopathologists classify SCC by microscopic appearance. The microscopic appearance allows dermatopathologists to determine the aggressiveness of the SCC and to assign a grade to the tumor. The grade is an important indicator of the patient's survivability or need to worry about the future.

......Dermatopathologists use the Borders' System to grade SCC's. The SCC grading system designed by Borders in 1921 has withstood the test of time. Borders' System uses four grades of SCC, I, II, III and IV. Each grade indicates the proportion of mature cells to immature cells that are found when viewing the biopsy under a microscope. Mature cells are typical cells, differentiated toward normal. Immature cells are atypical (not typical) cells, undifferentiated toward normal (exhibiting abnormal growth).

......Within any given specimen of SCC, there may be isolated areas of differing degrees of atypia. Therefore, a large biopsy should be taken of suspected SCC, as is the tradition, and the section with the least differentiation, i.e. the highest grade, should be said to represent the tumor. That way, doctors will not undertreat the SCC and cost a patient his/her life.

......The grade of SCC determines the length of a patient's survival and how the SCC should be treated. The higher the grade, the more harm the SCC can cause. However, a patient's immune status is important, as well. For example, AIDS patients and organ-transplant patients tend to have aggressive and deadly SCC. These patients should be suspicious of SCC on sun-damaged skin and should be very careful of the sun. Accurate SCC survival figures are dependent upon the most modern-day treatments. They will be included in a future section of this Web site.

......SCC is staged by whether or not it has invaded the body elsewhere. The more advanced the stage, the worse the prognosis (chances for survival). SCC is easily treated if detected early. It is especially important to detect SCC early or in the precancerous (actinic keratosis) phase on the lips and ears.

......Although 3mm margin excisions have been recommended in the past when standard surgical excision is used to treat SCC of the skin, Zitelli, a respected skin-cancer authority, has demonstrated that 5mm margins are likely the best when standard surgical excision is used. This need has been documented by special testing, using Mohs sections, of the edges of standard surgical excision sites.

.....As one can calculate (see Treating BCC and SCC), the use of 5mm borders calls for large obvious scars when standard surgical excision is used. Mohs Surgery is always the most accurate, with a cure rate of 98%, and tissue-sparing, it requires no margins, way to treat SCC. The Mohs surgeon does not have to guess. The microscope allows a trained American COLLEGE of Mohs Surgery Surgeon to determine when a layer is free of tumor. Because of budgetary problems and other money concerns, Medicare and many insurance policies will not cover the more expensive Mohs Surgery for SCC under some circumstances. Additionally, not all doctors are trained equally or adequately to perform Mohs Surgery (the most highly trained Mohs Surgeons being members of the American COLLEGE. Please beware the difference between members of the American COLLEGE of Mohs Surgery and members of the amazingly closely named American SOCIETY of Mohs Surgery. Please consult your medical insurance carrier.

......Bowen's disease (also known as intraepithelial squamous-cell carcinoma) and keratoacanthoma are two very common and special forms of SCC. The special types of skin cancer are each described at length elsewhere in the website. The author believes that each of case Bowen's and keratoacanthoma must be weighed and evaluated on its own circumstances and treated specially. This is especially true when considering body location, for example, the ears, eyelids, lips and nose.