Postfixation of cryostat sections improves tumor definition in Mohs surgery

Precise identification and localization of tumor is the key to success in Mohs micrographic surgery. In a pilot study, we demonstrated improvement in tumor definition and staining characteristics after formalin fixation of cryostat sections (postfixation) when compared with unfixed specimens. We further investigated the benefits of postfixation with a series of tissue fixatives and with varying fixation times. In all cases, postfixation was found to be beneficial. No improvement was noted by extending the postfixation time beyond 1 minute.