[Differential x-ray therapy of keratoacanthoma. A clinical case]

Differential radiotherapy is a way of making a diagnosis and treatment for keratoacanthoma at the same time. After having taken a punch biopsy in order to exclude basal cell carcinoma, we give an X-ray dose of 2500 r. This dose is sufficient to induce the healing of keratoacanthoma. If there is no tendency of healing, the tumor must be a squamous cell carcinoma. In this case, we apply the full tumor dose of totally 5000 r.