Information ⬇
Editors
AlexanderSalava
SariKoskenmies
Precancerous Lesions Preceding Squamous Cell Carcinoma (Actinic Keratosis and Carcinoma in Situ, or Bowen's Disease)
Essentials
- Actinic keratosis and carcinoma in situ (Bowen's disease) are precancerous lesions that untreated may progress to squamous cell carcinoma (SCC) Squamous Cell Carcinoma.
- Exposure to UV radiation from sunlight and genetic factors play a role in its development.
- Sun protection can be used to prevent or reduce the development or recurrence of precancerous lesions.
Epidemiology
- Common in people with light skin, on areas exposed to sunlight, at an older age
- Situated on the face (Images 1 2), bald scalp, upper earlobe margins, backs of the hands.
Diagnostics
- The lesions are usually clearly demarcated, erythematous patches with superficial hyperkeratosis (Image 3).
- The surface is usually rough on palpation, and the crust cannot be easily removed.
- Hyperkeratosis may be thick and horny (cornu cutaneum; Images 4 5 6).
- The diagnosis can be confirmed by skin biopsy but it is often made clinically when made by a physician with special expertise in skin cancer.
- If invasive SCC is suspected, a tissue biopsy should always be taken.
- This should be done if, for instance, the lesion is thick or mushy, tender on palpation or ulcerated, has grown or is pigmented, or if the patient has risk factors.
- The diagnosis of precancerous lesions on the lips, i.e. actinic cheilitis (Image 7) and in situ carcinoma, should always be confirmed by biopsy.
- Treatment depends on the location, size and thickness of the lesion.
- Small, single precancerous lesions should primarily be treated by freezing (due to the risk of leg ulcer, in lower limbs only after due consideration). See a serious of pictures in 8.
- Small precancerous lesions on the trunk and the limbs can also be treated by electrodessication or carbon dioxide laser.
- Treatment of large precancerous lesions or ones situated on cosmetically visible areas:
- photodynamic therapy Photodynamic Therapy for Actinic Keratoses or
- treatment with imiquimod cream
- actinic keratosis: 5% and 3.75% imiquimod
- carcinoma in situ: 5% imiquimod cream; NB: for basal cell carcinoma administration on 5 days a week for a period of 6 weeks, not an official indication.
- Mushy and thick carcinoma in situ should be removed surgically with a clinical margin of 3-5 mm and a histological margin of at least 1-2 mm.
- Actinic cheilitis of the lip should be treated in specialized care (by carbon dioxide laser and/or photodynamic therapy).
Follow-up examination
- On control visit after treatment (e.g. at 6-12 months), the treated area is assessed by visual inspection.
- It is essential that the scaling and hyperkeratosis have disappeared, and that there is no thickening or mushy feeling by palpation.
- Mild erythema or hypopigmented scar (cryo- or laser therapy, electrodessication) are common findings and do not require further treatments.
Specialist consultation
- In most cases, precancerous lesions can be treated by a physician familiar with such treatments in primary or outpatient care (cryotherapy, topical imiquimod cream therapy, excision of carcinoma in situ on the trunk or limbs).
- Specialized care should be consulted, as necessary.
- Actinic cheilitis and other precancerous lesions in the lip area should be treated in specialized care.
Evidence Summaries ⬆