Pre-cancerous skin lesions Flashcards
What are the clinical features of actinic keratoses?
- A flat or thickened papule or plaque
- White or yellow; scaly, warty or horny surface
- Skin coloured, red or pigmented
- Tender or asymptomatic
What sort of patients get actinic keratoses?
Actinic keratoses affect people that have often lived in the tropics or subtropics and have predisposing factors such as:
- Other signs of photoageing skin
- Fair skin with a history of sunburn
- History of long hours spent outdoors for work or recreation
- Defective immune system
Are actinic keratoses considered pre-cancerous?
It is considered precancerous or an early form of cutaneous squamous cell carcinoma.
How is a diagnosis of actinic keratosis made?
Actinic keratosis is usually easy to diagnose clinically or by dermoscopy (see actinic keratosis dermoscopy). Occasionally, a biopsy is necessary, for example, to exclude SCC, or if treatment fails.
What are the physical treatment options of actinic keratoses?
Cryotherapy using liquid nitrogen
Liquid nitrogen spray is required to ensure adequate depth and duration of the freeze. This varies according to lesion location, width and thickness. Healing varies from 5–10 days on the face, 3–4 weeks on the hands, and 6 weeks or longer on the legs. A light freeze for a superficial actinic keratosis usually leaves no mark, but longer freeze times result in hypopigmentation or scar.
Shave, curettage and electrocautery
Shave, curettage (scraping with a sharp instrument) and electrocautery (burning) may be necessary to remove a cutaneous horn or hypertrophic actinic keratosis. Healing of the wound takes several weeks or longer, depending on the body site. A specimen is sent for pathological examination.
Excision
Excision ensures the actinic keratosis has been completely removed, which should be confirmed by pathology. The surgical wound is sutured (stitched). The sutures are removed after a few days, the time depending on the size and location of the lesion. The procedure leaves a permanent scar.
What are the non-physical removal treatment options available for actinic keratoses?
Diclofenac is more often used as an anti-inflammatory drug. Applied as a gel twice daily for 3 months, it is fairly well tolerated in the treatment of actinic keratoses, but less effective than the other options listed here.
5-Fluorouracil is a cytotoxic agent. The cream formulation is applied once or twice daily for 2 to 8 weeks. 5-fluorouracil cream is sometimes combined with salicylic acid. Its effect may be enhanced by calcipotriol ointment.
Imiquimod cream is an immune response modifier. It is applied 2 or 3 times weekly for 4 to 16 weeks.
Photodynamic therapy (PDT) involves applying a photosensitiser (a porphyrin chemical such as methyl aminolevulinic acid) to the affected area prior to exposing it to a source of visible light.
Ingenol mebutate gel is effective after only 2–3 applications.
What is the definition of Bowen’s disease?
Squamous cell carcinoma in situ, often called Bowen’s disease, is a growth of cancerous cells that is confined to the outer layer of the skin.
What does Bowen’s disease look like?
A patch of Bowen’s disease starts as a small red scaly area, which grows very slowly. It may reach a diameter of a few centimetres across. It commonly occurs on sun-exposed skin, especially the face, scalp and neck, as well as the hands and lower legs. More than one area may be present. The development of an ulcer or lump on a patch of Bowen’s disease may indicate the formation of invasive squamous cell cancer.
How can Bowen’s disease be treated?
Freezing with liquid nitrogen. This is done in the clinic. It causes redness, puffiness, blistering or crusting, and may be slow to heal. It can be done in stages for large patches.
Curettage. This involves scraping off the abnormal skin under a local anaesthetic. The area then heals with a scab, like a graze.
Excision. The abnormal skin can be cut out,under local anaesthetic, provided it is not too large. This involves cutting around the lesion and stitching the skin which will leave a scar. If this method of treatment is chosen, you will be informed about the type of surgery planned and any other potential complications.
5-fluorouracil cream. This is a cream that may control or eradicate the disorder. There are different ways of using it, and, if it is felt to be the best treatment, the doctor who sees you will explain these to you. It works by killing the abnormal skin cells. This means that the skin will become red and look worse during treatment, and will then heal after the end of the course of treatment, once the abnormal cells have gone (see Patient Information Leaflet on 5-Fluorouracil Cream).
Imiquimod (Aldara) cream. This was originally developed for the treatment of genital warts, but imiquimod cream has been found useful in treating Bowen’s disease. It also causes inflammation of the skin during treatment (see Patient Information Leaflet on Imiquimod Cream).
Photodynamic therapy. A chemical is applied to the skin that makes the cells in the patch of Bowen’s disease sensitive to particular wavelengths of light. Light from a specially designed lamp is then shone onto the patch. This treatment can be painful and cause inflammation; however any inflammation should disappear within a few days (see Patient Information Leaflet on Photodynamic Therapy).
Radiotherapy and laser are other therapies occasionally used for the treatment of Bowen’s disease, although radiotherapy is not used for patches on the lower leg.
How will Bowen’s disease be diagnosed?
A patch of Bowen’s disease can look rather like other scaly skin conditions, such as psoriasis. For this reason a biopsy (a small sample of skin) may be needed to make the diagnosis.
What is lentigo maligna?
Lentigo maligna is an early form of melanoma in which the malignant cells are confined to the tissue of origin, the epidermis, hence it is often reported as ‘in situ’ melanoma. It occurs in sun damaged skin so is generally found on the face or neck, particularly the nose and cheek. It grows slowly in diameter over 5 to 20 years or longer.
What are the clinical features of lentigno maligna?
Lentigo maligna appears as a long-standing brown patch, most commonly on the face, which slowly enlarges and develops darker areas. Most in situ (very early) melanomas do not cause any symptoms.If a lentigo maligna is not treated promptly, it could become hard and lumpy, bleed, ooze or crust.
How is a diagnosis of lentigo maligna made?
A Dermatologist will examine the area carefully, usually with a magnifying device called a Dermatoscope, which is placed on the skin. This will help the Dermatologist decide whether the area needs to be looked at more closely under the microscope. This may involve removing the whole area under local anaesthetic (a procedure known as an excision) and the tissue is sent to the laboratory to be examined. If the area is too large to remove easily, a sample of it (an incisional biopsy) may be taken. If a lentigo maligna is found, the pathology report will provide information that will help to plan the next step in treatment.
What is the treatment of lentigo maligna?
The main treatment for lentigo maligna is surgical. There is no other treatment of proven benefit and usually no other tests are needed.
What distinguishes lentigo maligna on dermatoscope?
Facial pigmented lesions are characterised dermoscopically by pseudonetwork – this is pigmentation arising around prominent facial hair follicles, and several types of skin lesion may appear rather similar to lentigo maligna. However, lentigo maligna shows greater variation in the thickness of the lines making up the network, often forming an atypical rhomboid pattern associated with greyish dots, the structure tends to be irregular, and there is variation in colour.
What is a seborrhoeic keratosis?
A seborrhoeic keratosis is a harmless warty spot that appears during adult life as a common sign of skin ageing. Some people have hundreds of them.
What is the difference between the 3 types of naevi?
