<prompt> Squamous cell carcinoma can arise from-a Long standing venous ulcersb Chronic lupus vulgarisc Rodent ulcerd All of the aboveacaabbc  <response>: It is a carcinoma of the cells of epidermis that usually migrate outwards to the surface. Originate from prickle cell layer; Seen in 40 years of age MC skin cancer in darkly pigmented races 2nd MC skin cancer in light skinned races MC causative factor: Sunlight MC site: Ears, cheeks, lower lip and back of hands 