Final answer:
Basal cell carcinoma is the most common benign epithelial tumor of the oral mucosa. It occurs in basal cells of the epidermis and rarely spreads to other parts of the body.
Step-by-step explanation:
The most common benign epithelial tumor of the oral mucosa is basal cell carcinoma. Basal cell carcinoma is a type of skin cancer that occurs in basal cells of the epidermis. It rarely metastasizes, which means it does not spread to other parts of the body. Instead, it can generally be cured with a biopsy, where the lesion is removed and analyzed in a medical lab.