<prompt> Which is related to sunlight exposureActinic keratosisMolluscum contagiosumIcthyosisBasal cell carcinoma  <response>: A i.e. Actinic Keratosis Etiological Factors Premalignant lesions for Squamous Cell CA Actinic Solar KeratosisQ, Arsenic As Keratosis Bowens diseaseQ Intra-epidermal epithelioma Chemical carcinogens eg. tar, pitch, Arsenic DLEQ, Dystrophic epidermolysis bullosa Erythema ab igne persistent heat injury Erythroplasia of queyratQ Bovvens ds. of glans penis Epidermal naevus Epidermodysplasia verruciformis Giant way tumor of genitalia, Genodermal disease i.e. XerodermaQ Hyperophic lichen planusQ Human Papilloma virus infection more commonly in immunosuppressed renal transplant patients Xeroderma pigmentosa Genodermal diseaseQ UV radiation - UV-BQ Actinic Solar Keratosis AK These are hyperkeratotic lesions that develop in response to prolonged exposure to ultraviolet radiation i.e. on chronically light exposed adult skinQ. Risk factors for development of AK include old age, male gender, fair skin that easily burns and freckles, blondred hair, light colored eyes, immunosuppression, gentic syndromes like XP, Blooms and Rothmund-Thomoon syndromes, prior history of AK or other skin cancer and most impoantly cumulative IV radiation exposureQ. - Historically being considered premalignant lesionsQ with focal areas of abnormal proliferation and differentiation that carry a low risk 0.2 of progression to invasive sauqmous cell carcinomaQ. However, now these are defined as malignant neoplasm with intra epithelial SCCs in evolution. - It is raised, pink or grey, scaling or way hyperkeratotic plaque or papule with alternating parakeratoses hyperkeratosis in histology. Premalignant lesion Predisposed Cancer Actinic Solar KeratosisQ Squamous cell carcinoma Bowens ds. intra-epidermal- epitheliomaQ Squamous cell CA ErythroplasiaQ of QueyratQ bowens ds. affecting glans penis Squamous cell CA Lan ago maligna Hutchinsons freckleQ Malignant Melanoma Also Know -UV - radiation Xeroderma pigmentosa are risk factors for all 3 types of skin cancer Basal, Squamous Cell, Melanoma. Lentigo maligna Hutchinsons freckle is premalignant lesion for malignant melanomaQ. 