Imiquimod treatment of AK resulted in superior sustained clearance and cosmetic outcomes compared with cryosurgery and 5-FU. It should be considered as a first line therapy for sustained treatment of AK.

Basal cell carcinoma (BCC) is a malignant epithelial neoplasm of the skin preferentially affecting male caucasians and is rarely observed in patients with more intense skin pigmentation. A characteristic feature of BCCs are their extremely low risk to metastasize. Epidemiological data indicate that the overall incidence is increasing worldwide significantly by about 3-10% per annum.(1-3) Based on the increasing incidence of this usually not life-threatening tumour BCC appears to develop into a growing public health problem. This review elucidates the risk factors for the development and for the progression of BCC leading to an improved understanding of this tumour.

Background: Actinic keratoses (AK) represent cutaneous carcinoma in situ and have previously been evaluated by reflectance confocal microscopy (RCM). Treatment of AK with imiquimod (IMIQ) 5% cream has been shown to ‘highlight’ subclinical lesions. Objective: The aim of this study was to test the applicability of RCM for noninvasive monitoring of actinic field cancerization and detection of subclinical AK. Subjects and Methods: AK and surrounding skin sites with no apparent AK of 11 volunteers were selected for imaging and subsequently classified as ‘clinical’ and ‘subclinical’ AK. IMIQ was used 3 times weekly for 4 weeks. Results: RCM was able to detect morphologic features of AK in both clinical and subclinical AK; features were more pronounced in clinical lesions. The immunomodulatory response induced by IMIQ was visualized by RCM. Conclusion: Our findings indicate that RCM allows noninvasive monitoring of treatment response in vivo and permits early detection of subclinical AK, thus substantiating the incentive for therapy.

Actinic keratosis is a UV light-induced lesion and develops mostly in fair-skinned patients being susceptible to solar damage. The term actinic keratosis (AK) describes clinically ill-defined reddish to reddish-brown scaly lesions on erythematous base in areas damaged severely by sunlight. The term does not imply anything about the biology or histopathology. Actinic keratoses (AKs) have been recognized as precursor of cancer or of precancerous lesions in the past but today they are considered as an early in situ squamous cell carcinoma (1,2) and are categorized in several classifications with subdivisions into three grades depending on the amount of atypical keratinocytes in the epidermis.(3-6) The incidence of development of AK in caucasians increases with age, proximity to the equator and outdoor occupation. Australia has the highest skin cancer rate in the world. AKs are discovered in up to 40-50% of the Australian population older than 40 years.(7) AKs are the most common malignant lesion of the skin.(8-12).

Minimally invasive diagnostic tools have received increased attention for diagnosis, screening and management of nonmelanoma skin cancer (NMSC). Several modalities are commercially available, including high frequency ultrasound, optical coherence tomography and confocal microscopy. While systematic clinical analyses are often lacking, recent reports have shown promising results for reflectance confocal microscopy (RCM) for diagnosis of actinic keratoses and basal cell carcinoma.