Advisory on delayed fading caused by the use of a xylene substitute for frozen tissue specimen staining in micrographic surgery.

Background: The use of xylene substitutes is becoming more common in the setting of micrographic surgery frozen tissue section staining, and dermatologic surgeons need to be aware of possible undesirable delayed effects of using these agents and the possibility of modifying H&E staining protocols to prevent delayed fading. This report demonstrates an undesirable outcome of using an isoparaffinic aliphatic hydrocarbon as a xylene substitute, implementation of a quality improvement intervention to eliminate frozen section slide fading in the setting of micrographic surgery tissue processing, and recommendations for the modification of protocol when using a xylene substitute.

Clinical and laboratory information: Frozen section slides processed with xylene and xylene substitute were analyzed by histotechnicians, a dermatopathologist, and a micrographic surgery surgeon at 1-week and 1-month intervals. The use of a standard H&E protocol resulted in zero stains fading when using xylene as a clearing agent, but delayed fading when using a xylene substitute.

Discussion: Using an isoparaffinic aliphatic hydrocarbon as a xylene substitute can lead to excess water carryover, which may result in delayed hematoxylin fading in micrographic surgery tissue staining, so using this xylene substitute likely requires modification to the dehydration phase and tap water immersion phase to prevent fading.