Mucin stain on frozen sections - A rapid 3-minute method

Context.-The importance of frozen-section diagnoses in the practice of path ology cannot be overemphasized. In some cases, the use of a mucin stain can greatly aid in the diagnosis. Since few methods for mucin staining have be en described that can be used in the frozen-section setting, we developed o ne such staining procedure for mucin. Objective.-To develop a rapid mucicarmine staining technique to be used on frozen sections that does not significantly delay overall turnaround time. Design.-A standard mucicarmine staining technique was modified by using a c oncentrated mucicarmine stain and a microwave oven, to reduce the total sta ining time to 3 minutes or less. Frozen tissue from normal colonic mucosa w as used as a control, and skin from extramammary Paget disease for evaluati on of margins was used as a case. Results.-The rapid mucicarmine stain successfully demonstrated the presence of mucin on frozen-tissue sections. Mucin stained deep rose, and the conne ctive tissue stained green. Conclusion.-This rapid and simple mucin staining technique can be used on f rozen sections with no significant effect on the overall turnaround time, t hereby aiding rapid diagnosis on frozen sections.