Method for using cryogenic agents for treating skin lesions

A method of cryogenically treating a benign skin lesion comprising the steps of:

• (a) placing a hollow fluid retaining device, having a side wall defining a bottom open end of a size slightly greater than a skin lesion to be removed by cryosurgery and a top open end, in an essentially upright position on a patient's skin in a manner whereby said bottom open end seals against the patient's skin entirely surrounding said skin lesion and said top open end is above said bottom open end,
• (b) introducing into said top open end of said upright fluid retaining device for a period of about 3 to 10 seconds a liquid cryogenic agent to cause formation of a liquid pool of said cryogenic agent to contact directly the entire area of said skin lesion,
• (c) terminating said introducing of said cryogenic agent step,
• (d) retaining said hollow fluid retaining device in said upright position surrounding said skin lesion for a period of about 10 to 25 seconds after said introducing step has been terminated in order to retain said liquid pool of cryogenic agent within said bottom open end of said fluid retaining device and in contact directly with said skin lesion for a period of time to permit said cryogenic agent to reduce the temperature of said skin lesion to a temperature such that permanent, irreversible rupture of cellular membranes of cells of said skin lesion occurs while said cryogenic agent is evaporating,
• (e) subsequently removing said fluid retaining device from said upright position after said liquid cryogenic agent has evaporated, and
• (f) permitting said skin lesion to completely thaw over a period of about 45 to 65 seconds after said step of removing said fluid retaining device, and sequentially repeating said steps of (a), (b), (c), (d) and (e).