anatomy tissues

Skin Cancer: Carcinoma & Melanoma

| December 12, 2013 | 2 Comments

Loss of homeostasis within body cells and organs always reveals itself on the surface of the skin, sometimes in drastic ways. The skin can develop over a 1000 different ailments and conditions. Usually, skin disorders are either viral, bacterial, or some type of yeast infection. Less common, but far more dangerous skin conditions include skin cancer and burns.

Skin Cancer

One out of every five Americans will develop skin cancer. Most tumors that arise are usually benign and don’t spread to other areas of the body. However, some skin tumors are malignant (cancerous) and invade other areas.

The single most important risk factor for skin cancer is excessive exposure to UV radiation from sunlight, because it damages DNA bases. UV radiation also appears to disable a tumor suppressor gene called p53, or the patched (ptc) gene. In a number of cases, frequent irritation caused by infections and chemicals seems to be a predisposing factor.

Interestingly enough, sunburned skin accelerates the production of Fas, a protein that causes genetically damaged skin cells to commit suicide, thereby reducing the risk of mutations that could cause sun-linked skin cancer. The death of these cells causes the skin to peel after a sunburn.

Ladies and gentlemen, sorry to burst your bubble, but there is no such thing as a “healthy tan”, but there is good news, some newly developed skin lotions can fix damaged DNA before the involved cells become cancerous. These lotions contain tiny oily vesicles (liposomes) filled with enzymes that initiate the repair of NA mutations caused by sunlight. T

Basal cell carcinoma, squamous cell carcinoma, melanoma. Skin cancer.

Basal cell carcinoma, squamous cell carcinoma, melanoma. Image courtesy of the National Cancer Institute.

he liposomes penetrate the epidermis (upper layer of skin) and enter keratinocytes, eventually making their way into the nuclei where they bind to specific sites where two DNA bases have fused. There, they begin a DNA repair process that’s completed by cellular enzymes. The three main forms of skin cancer are basal cell carcinoma, squamous cell carcinoma, and melanoma.

Basal Cell Carcinoma

Basal cell carcinoma is the least malignant and most common form of skin cancer, it accounts for 80% of cases in the United States. With this type, stratum basale cells proliferate and invade the dermis and hypodermis. The cancer lesions usually occur on sun-exposed areas of the face and appear as shiny, dome-shaped nodules that eventually develop a ulcer in the center with a pearly edge. Basal cell carcinoma grows fairly slow and metastasis rarely occurs without it being noticed. Full cure by surgical excision is the rule in 99% of cases.

Squamous Cell Carcinoma

Squamous cell carcinoma is the second most common form of skin cancer and arises from keratinocytes in the stratum spinosum. The lesion usually appears as a scaly red papule, is small, round, and elevated. Most often, they arise on the head (ears, scalp, lip), and hands. Squamous cell carcinoma will grow rapidly and metastasize if not removed. The chances of a complete cure are good if the lesion is caught early and removed surgically (or by radiation therapy).

Melanoma

Melanoma (cancer of melanocytes) is the most dangerous form of skin cancer because it is highly metastatic and resistant to chemotherapy. Currently, it only accounts for 2-3% of skin cancer cases, but its incidence rate is increasing rapidly (3-8% per year in the United States). Melanoma can begin wherever there is pigment. This form of cancer usually appears spontaneously and around one-third of cases develop from pre-existing skin tags and moles. It usually appears as a spreading brown to black patch that metastizes (spreads) rapidly to surrounding blood and lymph vessels. If you want to survive melanoma, the key is early detection. If the lesion grows over 4 mm thick, the chance of survival is poor. Standard therapy for melanoma includes surgical excision accompanied by immmunotherapy (immunizing the body against the cancer cells).


The American Cancer Society suggests everyone should examine their skin regularly to check for new moles and changes in pigment. A good way to check your skin for melanoma is to use the ABCD rule:

  1. Asymmetry – the two sides of the pigmented spot or mole do not match.
  2. Border irregularity – the borders of the lesion exhibit indentations.
  3. Color – the pigmented spot contains several colors (browns, blacks, tans, and sometimes even blue or red).
  4. Diameter – the spot is larger than 6 mm in diameter (about the width of a normal pencil).

So, there you have it, the ABCD rule: asymmetry, border irregularity, color, and diameter. (note: some healthcare professionals add an E for elevation above the skin surface)

I hope this article was helpful and if you have any questions feel free to leave a comment or send us an email.

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Category: Body Systems, Integumentary

Comments (2)

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  1. I have what a doctor had told me a few years ago, as epithelial skin irregularities. He felt they were not worth checking. When they first appeared a few years ago, they were colorless. About four years later, that is, today, 7/5/2014, the two I am concerned about now have color to them on my waist, left side; you can push in on them. They look as though they may be full of a fluid. Problem is, today one of them has a pink coloration to it, feeling slightly itchy, and kind of red around the bump. The other one very close to the pink colored one, now has a somewhat red coloration to it, almost like as if blood has welled up inside the bump. I think I better get to a dermatologist to have them sliced off to check them for potential cancer. Any comments??

    • Hello Kathaleen,

      I must inform you I am a Registered Nurse so am unable to make a definitive diagnosis. However, your concerns are warranted. You indicate the skin irregularities are located around your waist area. Because of our clothing and bending, this is an area on our bodies that endures a lot of rubbing, pressure and moisture. So, the location alone may be making them worse. There are many skin irritations, blisters and pustules other than cancer that may be fluid filled, pink, red and itching so I would not immediately draw any conclusions. Your decision to see a dermatologist is a good one, especially since you have had these for a few years and you have seen a significant change in them. Dermatologists do not necessarily need to remove them entirely. They can do a skin scraping for diagnosis. However, perhaps it would give you piece of mind to have them removed.

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