Skin cancer can be divided into two broad categories:

Melanoma which accounts for 4% of all skin cancers and non-melanoma skin cancers that account for 96% of skin cancers

These 2 types of skin cancer behave very differently

Melanoma Skin Cancer
Non-melanoma Skin Cancer

Precursor lesion – Dysplastic moles

Types of melanoma

In situ (confined to skin)

Invasive (potential to spread)

Risk increased by burning UV exposure,

Family history, fair skin, pre-existing moles

More common in people with many moles

Genetic predisposition

May occur anywhere on skin

May spread to internal organs

Early detection improves survival

Significant mortality

Presents as changing pigmented lesion

Precursor lesion – actinic keratosis

Types of non-melanoma skin cancer

Basal cell carcinoma (never spreads)

Squamous cell carcinoma (rarely spreads)

Risk increased by total UV exposure, fair skin and immunosuppression

more common fair skinned people

frequent in immunosuppressed patients

mostly on head, scalp, neck and hands

Usually localised spread only

early detection improves outcome

surgery usually curative

inflamed, crusted or bleeding lesion

Melanoma Skin Cancer

Melanoma is a serious form of skin cancer that begins in cells known as melanocytes. While it is less common than basal cell carcinoma (BCC) and squamous cell carcinoma (SCC), melanoma is far more dangerous because of its ability to spread to other organs more rapidly if it not treated at an early stage. Finding melanoma at an early stage is crucial; early detection can vastly increase your chances for cure. Look for anything new, changing or unusual on both sun-exposed and sun-protected areas of the body. Melanomas commonly appear on the legs of women, and the number one place they develop on men is the trunk. Keep in mind, though, that melanomas can arise anywhere on the skin, even in areas where the sun doesn’t shine.Most moles, brown spots and growths on the skin are harmless – but not always. The ABCDEs and the Ugly Duckling sign can help you detect melanoma. The Ugly Duckling is another warning sign of melanoma. Most normal moles on your body resemble one another, while melanomas stand out like ugly ducklings in comparison. This highlights the importance of not just checking for irregularities, but also comparing any suspicious spot to surrounding moles to determine whether it looks different than its neighbors.


sun avoidance or protection

Early detection

self examination, medical examination, total body photography, dermoscopic imaging of individual lesions

Early intervention

surgical removal suspicious lesions

Non-melanoma skin cancer

Clinical features 

Texture:               flat to slightly raised, scaly and or rough

Size:                       from a couple of millimetres up to 2 cm in diameter

Colour:                 may vary from skin coloured to red, tan, pink or silvery

Location:              areas exposed to a lot of UV light such as the scalp, face, ears, lips, and the back of the hands and forearm

Basal cell carcinoma

Basal cell carcinoma (BCC) is the most common form of skin cancer and the most common cancer in humans. BCCs arise from abnormal, uncontrolled growth of basal cells in the skin.

Because BCCs grow slowly, most are curable and cause minimal damage when caught and treated early

Clinical features:

  1. An open sore that does not heal, and may bleed, ooze or crust. The sore might persist for weeks, or appear to heal and then come back.
  2. A reddish patch or irritated area, on the face, chest, shoulder, arm or leg that may crust, itch, hurt or cause no discomfort.
  3. A shiny bump or nodule that is pearly or clear, pink, red or white. The bump can also be tan, black or brown, especially in dark-skinned people, and can be mistaken for a normal mole.
  4. A small pink growth with a slightly raised, rolled edge and a crusted indentation in the center that may develop tiny surface blood vessels over time.
  5. A scar-like area that is flat white, yellow or waxy in color. The skin appears shiny and taut, often with poorly defined borders. This warning sign may indicate an invasive BCC.
Squamous cell carcinoma (SCC)

SCC occurs when DNA damage from exposure to ultraviolet radiation or other damaging agents trigger abnormal changes in the squamous cells.

SCCs can appear as scaly red patches, open sores, rough, thickened or wart-like skin, or raised growths with a central depression. At times, SCCs may crust over, itch or bleed. The lesions most commonly arise in sun-exposed areas of the body.

SCCs look different on everyone

SCC of the skin can develop anywhere on the body but is most often found on exposed areas exposed to ultraviolet (UV) radiation like the face, lips, ears, scalp, shoulders, neck, back of the hands and forearms. SCCs can develop in scars, skin sores and other areas of skin injury. The skin around them typically shows signs of sun damage such as wrinkling, pigment changes and loss of elasticity. SCCs can appear as thick, rough, scaly patches that may crust or bleed. They can also resemble warts, or open sores that don’t completely heal. Sometimes SCCs show up as growths that are raised at the edges with a lower area in the center that may bleed or itch.

Non-Melanoma skin cancer



daily sun protection (Slip on a shirt , slap on a hat, slop on the sun screen)

Early detection

Medical examination of at risk individuals and suspicious lesions i.e. new, crusted or bleeding lesions on at risk site

Medical intervention

Cryosurgery, surgical excision, Laser ablation, topical chemotherapy, photodynamic therapy