Basal cell carcinoma is the most common form of skin cancer. Ultraviolet exposure and decreased DNA repair capacity are known risk factors for the development of basal cell carcinoma. However, while sunlight is critical in basal cell carcinoma pathogenesis, the relationship between exposure and tumor site and histology is unclear. Basalioma occurs in middle-aged humans, dogs and cats with no sex predilection. The tumors occur most commonly on the head, neck, and thorax. Three major histopathologic variants of basal cell carcinoma are solid, keratinizing (basosquamos), cystic, ribbon and medusoid. Generally, basal cell tumors are benign, but rare reports of metastasis exist. The prognosis is fair to good.