Treatment of Melanoma Excision Wound With 50% Zinc Chloride Solution Astringent—Mohs Melanoma Surgery Without the Paste

摘要

BACKGROUND: Dr. Frederic Mohs believed that surgery can spread a melanoma; to prevent this, he applied an inactive black paste vehicle containing the active ingredient 50% zinc chloride solution to melanomas to kill and fix (i.e., preserve) tissue; this is termed fixed-tissue surgery . A statistically significant, 53-percent, five-year melanoma survival improvement in 103 consecutive cases was reported for fixed-tissue surgery compared to five-year survival for cases treated with conventional surgery ( p =0.003). Nine physicians, including the author, contributed to a melanoma registry of 179 cases between 1981 and 1991, and in 64 five-year determinate cases of thin melanomas (0.85mm), survival was improved by 60 percent with zinc chloride paste simply applied after excision to the open fresh-tissue wound compared to conventional surgery (95.7% five-year survival with zinc chloride applied to the excision wound vs. 88.9% five-year survival with conventional fresh-tissue excision only, hazard ratio 0.37). When applied to an open fresh excision wound in either a solution or paste form, zinc chloride penetrates instantly; the author has found both forms to be equally effective. In solution form, the application technique is simple and similar to the astringent 20% aluminum chloride solution applied with sterile gauze or Q-tip, but the inactive paste vehicle requires special dressings. Additionally, the inactive paste used by Mohs contains stibnite antimony; therefore, it cannot be formulated to USP standards and is not recognized by the FDA as a generally safe substance. However, zinc chloride is recognized by the FDA as a generally safe substance, and the 50% solution can be formulated by a compounding pharmacist to USP standards. 50% zinc chloride solution penetrates deeply and kills tissue and should not be used without previous biopsy confirmation of melanoma or melanoma in situ . The killing of tissue on the melanoma excision wound by the zinc chloride causes the wound to become deeper and wider, and therefore a smaller and thinner excision margin can be removed.