Intense cryotherapy of superficial basal cell carcinoma on the back.
Intense cryotherapy may be suitable for the treatment of small superficial basal cell carcinomas and small carcinoma in situ lesions. The technique is only suitable for use by a physician with particular expertise in cryotherapy. It must never be applied below knee level, as it can easily lead to chronic ulceration in this area. In primary health care, the technique should basically not be used for lesions in the head or neck area at all. When treating lesions in the head area, the cosmetic and functional results and risk of recurrence should be carefully considered. It is important to perform a checkup 3-6 months after the treatment.
First use a marker to draw the outline of the lesion and the margin. A freeze margin of about 3 mm is normally used. The outline of the margin is marked here with a solid line. The area should be marked before applying an anaesthetic because detecting the outline may be difficult afterwards (due to the effect of adrenaline in the anaesthetic solution, for example). After marking, disinfect the area to be treated and infiltrate a local anaesthetic (here we use an injection solution with 10 mg/ml lidocaine and 10 µg/ml adrenaline). When the area is numb, use a curette for superficial removal of abnormal tissue (here we use a 7-mm curette). Basal cell cancer tissue is usually easy to remove and is softer in consistence than normal skin. Oozing can be stopped by pressing gently with a cotton swab dipped in ferric chloride or aluminium chloride solution (here we use aluminium chloride).
Freeze the lesion white to establish a halo thaw time of about one minute (withdrawal of the white thaw line from the margin to the outline of the lesion). Allow the entire lesion to thaw properly, and then repeat freezing. There will be a weeping superficial ulcer and a clear blister. The treatment practically always leaves a permanent light scar that will be quite visible on dark skin but practically unnoticeable in people with very light skin.
Video: Timo Ruohoalho, text: Alexander Salava and Timo Ruohoalho
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