What is Basal Cell Skin Cancer?
The most frequently occurring form of skin cancer is Basal Cell Carcinoma (BCC). BCCs are abnormal, uncontrolled growths or lesions that arise in the skin’s basal cells, which line the deepest layer of the epidermis (the outermost layer of the skin). BCCs often look like open sores, red patches, pink growths, shiny bumps, or scars and are usually caused by a combination of cumulative and intense, occasional sun exposure.

BCC almost never spreads (metastasizes) beyond the original tumor site. Only in exceedingly rare cases can it spread to other parts of the body and become life-threatening. It shouldn’t be taken lightly, though: it can be disfiguring if not treated promptly.

In 2010, an estimated 2.8 million cases of BCC were diagnosed in the U.S., and the figures have continued to climb. In fact, BCC is the most frequently occurring form of all cancers. More than one out of every three new cancers is a skin cancer, and the vast majority are BCC

What is Squammous Cell Skin Cancer?
The second most common form of skin cancer, Squamous cell carcinoma (SCC) is an uncontrolled growth of abnormal cells arising in the squamous cells, which compose most of the skin’s upper layers (the epidermis). SCCs often look like scaly red patches, open sores, elevated growths with a central depression, or warts; they may crust or bleed. They can become disfiguring and sometimes deadly if allowed to grow. An estimated 700,000 cases of SCC are diagnosed each year in the US, and between 3,900 and 8,800 people died from the disease in the US in 2012. Incidence of the disease has increased up to 200 percent in the past three decades in the US.

SCC is mainly caused by cumulative ultraviolet (UV) exposure over the course of a lifetime; daily year-round exposure to the sun’s UV light, intense exposure in the summer months, and the UV produced by tanning beds all add to the damage that can lead to SCC.

SCCs may occur on all areas of the body including the mucous membranes and genitals, but are most common in areas frequently exposed to the sun, such as the rim of the ear, lower lip, face, balding scalp, neck, hands, arms and legs. Often the skin in these areas reveals telltale signs of sun damage, including wrinkles, pigment changes, freckles, “age spots,” loss of elasticity, and broken blood vessels.

What is Melanoma?
The most dangerous form of skin cancer, these cancerous growths develop when unrepaired DNA damage to skin cells (most often caused by ultraviolet radiation from sunshine or tanning beds) triggers mutations (genetic defects) that lead the skin cells to multiply rapidly and form malignant tumors. These tumors originate in the pigment-producing melanocytes in the basal layer of the epidermis. Melanomas often resemble moles; some develop from moles. The majority of melanomas are black or brown, but they can also be skin-colored, pink, red, purple, blue or white. Melanoma is caused mainly by intense, occasional UV exposure (frequently leading to sunburn), especially in those who are genetically predisposed to the disease. Melanoma kills an estimated 9,940 people in the US annually.

If melanoma is recognized and treated early, it is almost always curable, but if it is not, the cancer can advance and spread to other parts of the body, where it becomes hard to treat and can be fatal. While it is not the most common of the skin cancers, it causes the most deaths. The American Cancer Society estimates that at present, more than 135,000 new cases of melanoma in the US are diagnosed in a year. In 2015, an estimated 73,870 of these will be invasive melanomas, with about 42,670 in males and 31,200 in women.

The ABCDE’s of Melanoma

Skin cancer can develop anywhere on the skin. Ask someone for help when checking your skin, especially in hard to see places. If you notice a mole that is different from others, or that changes, itches or bleeds (even if it is small), you should see a dermatologist.

A: Asymmetry – the two halves of the lesion are not mirror images.
B: Border Irregularity: The edges are blurred, jagged or notched.
C: Color Variation: The pigment is not uniform. The lesion has shades of tan, brown, or black.
D: Diameter: Lesions are bigger than a pencil eraser.
E: Evolution or Change: Lesions show growth.

(chart source: AAD.org)

(content source: skincancer.org)