Cryosurgical treatment of ocular squamous cell carcinoma of cattle.

A total of 718 ocular squamous cell carcinomas of cattle were treated with various cryosurgical units and techniques during a 2.5-year study. In 609 of the lesions, a single freeze was used, with a cure rate (total regression) of 66%. In 109 lesions treated with a double freeze-thaw cycle (rapid freeze to - 25 C, and unaided thaw followed immediately by refreezing to -25 C), the cure rate was 97%. Cryosurgical units designed for delivery of liquid nitrogen provided a more rapid rate of freezing and, thus, a higher cure rate than did units designed for delivery of nitrogen vapor. It was concluded that cryosurgery for treatment of squamous cell carcinoma is a simple and rapid procedure; is economical; provides analgesia itself, due to sensory nerve injury; requires minimal preoperative and no postoperative medication; causes minimal side effects; may be repeated; and is excellent for use on suspect premalignant lesions.