J Clin Aesthet Dermatol. 2020;13(8):49–50 by Brian Wanner, DO; Stephanie Saridakis, DO;
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.