DermNet NZ, a website of the New Zealand Dermatological Society. Provides good information on cryotherapy, a preferred treatment for small and superficial nonmalignant moles or for basal cell or squamous cell carcinomas (sometimes called Bowen’s Disease). Cryotherapy refers to a treatment in which surface skin lesions are frozen. The procedure involves spraying of the lesion with a substance that most commonly is liquid nitrogen to freeze it. A blister and scab may form, and gradually within a few days the blister dries up and the scab drops off. The skin may return to normal, or may exhibit a white patch where the lesion was removed.