Look out for irregular borders
Dr Debbie Norval examines some of the most common pre-cancerous growths from a discoloured patch on the skin to a mole that has changed in appearance
Actinic Keratosis or Solar Keratosis
Actinic Keratoses are the most common sun-related pre-cancerous growths noted in fair-skinned individuals. They are benign (non-malignant) but if left untreated, Actinic Keratosis has the potential to develop into Squamous Cell Carcinoma which is malignant.
Actinic Keratosis appears as crusty, “dry” scaly bumps that are rough textured and sandpaper-like to the touch. They can be skin-coloured, reddish or yellowish, tan or dark brown in colour. They can gradually enlarge, thicken and become more elevated and form “cutaneous horns”.
They appear mainly on the face, especially on the nose, ears, temples, forehead, neck, and sometimes on or around the lips. They also commonly arise on the top of the forearms and hands and on the scalp of balding men.
Treatment
- Cryosurgery: Freezing with liquid nitrogen is an old fashioned form of treatment that can result in scarring and loss of pigmentation.
- Electrocautery using Lamprobe is very effective and precise with no scarring,
- Tixel has been used to treat solar keratosis
- Topical chemotherapy with a prescription cream or lotion.
- Photodynamic therapy (PDT) using the Omnilux light
Squamous Cell carcinoma (SCC)
Squamous Cell Carcinoma is a cancer that begins in the squamous cells, which are flat, thin skin cells that resemble fish scales under a microscope. The earliest form of Squamous Cell Carcinoma is Actinic Keratosis or Solar Keratosis.
Squamous Cell Carcinoma begins as a firm red nodule or scaly crusted flat lesion that often appears as a non-healing sore, bump, or ulcer. Rapidly growing Squamous Cell Carcinoma forms a mound with a central crater and this is called a keratoacanthoma.
Treatment
Most Squamous Cell Carcinoma’s can be completely removed with relatively minor surgery. This is done by a Plastic Surgeon or a Dermatologist. Larger and deeply penetrating SCCs and those found next to or on mucous membranes (e.g. on lips), are considered more dangerous and must be treated more thoroughly. Depending on the size, location and aggressiveness of the tumour, treatment may include one or more of the following:
- Electrodessication and Curettage: The surface of the skin cancer is removed with a scraping instrument or curette and then the base of the tumour is seared with an electric needle
- Surgical excision
- Cryosurgery: Freezing with liquid nitrogen
- Mohs micrographic surgery
- Radiation therapy: This may be an option for treating large cancers on the eyelids, lips and ears or areas that are difficult to treat surgically, or for tumours too deep to cut out
- Topical chemotherapy with creams or ointments e.g 5 – Fluorouracil (5-FU), Efudex, Fluoroplex or Aldara
- Laser therapy
Basal Cell Carcinoma (BCC)
Basal Cell Carcinoma is the most common type of skin cancer, often referred to as a Rodent Ulcer. A Basal Cell Carcinoma usually begins as a small, dome-shaped bump that has blood vessels usually visible with a device such as a SkinLite.
The texture of the bump is often “pearly”, shiny and translucent. It can be confused with a flesh coloured mole, so a biopsy is performed to verify this. Basal Cell Carcinomas can contain melanin, so that they look darker rather than shiny in some cases. Basal Cell Carcinomas grow slowly taking months to years to develop. They may have a small scab on their surface. It is easily treated and cured in most cases. Basal Cell Carcinomas are slow growing and very rarely metastasize (spread). They should not be ignored though, as they can extend below the skin and cause considerable damage to nerves, cartilage and bone. Although Basal Cell Carcinoma qualifies as a cancer, its harmful effects, if recognised and treated early, are usually minor.
Treatment
- Electrodessication and Curettage: The surface of the skin cancer is removed with a scraping instrument (curette) and then the base of the tumour is seared with an electric needle
- Surgical excision: In this procedure, which is used for both new and recurring tumours, the cancerous tissue and a surrounding margin of healthy skin is cut out
- Cryosurgery: Freezing with liquid nitrogen
- Mohs micrographic surgery: During this procedure, an experienced Mohs surgeon removes the tumour layer by layer, examining each layer under the microscope until no abnormal cells remain
- Radiation therapy
- Topical chemotherapy with cream or ointments e.g 5 – Fluorouracil (5-FU), Efudex, Fluoroplex or Aldara. This avoids surgery, however this option includes discomfort and a lower cure rate
- Laser surgery
Malignant Melanoma
Malignant Melanoma is the most serious type of all skin cancers. It can arise on normal skin or from an existing mole. If not treated promptly, it can metastasize into other areas of the skin, lymph nodes or internal organs.
Melanocytes are found throughout the lower part of the epidermis. They produce melanin, which is the pigment that gives skin its natural colour. When skin is exposed to the sun, melanocytes make more pigment causing the skin to tan or darken. Malignant melanoma is a disease in which malignant (cancer) cells form from these melanocytes.
Malignant Melanoma may have some or all of the following “ABCDE” features
- A Asymmetry one half is unlike the other half
- B Borders that are irregular or notched
- C Colour that is varied (brown, black, pink, blue-gray, white, or mixtures of these colours)
- D Diameter that is greater than 6mm although these can be smaller
- E Evolving, or change in a pre-existing mole. Any change in size, elevation, or any new symptoms such as itching, bleeding, or crusting; particularly a mole that looks different from the rest
Treatment
- Urgent surgical excision is the treatment of choice and should be performed by a dermatologist or plastic surgeon who has experience in dealing with malignant melanoma.