A keratoacanthoma is a rapidly growing, well-differentiated neoplasm of squamous epithelium considered a low-grade squamous cell carcinoma. It typically has a distinct crater-shaped appearance and usually occurs as a solitary nodule on the sun-exposed skin of individuals aged 60 years and older. Men are more commonly affected than women, and individuals with lighter skin colors are at greater risk. If left untreated, most keratoacanthomas spontaneously involute and resolve within 6 months, leaving an atrophic scar. Risk factors for keratoacanthomas include ultraviolet radiation, human papillomavirus infection, immunosuppression, and certain medications.