Mucin stain on frozen sections: a rapid 3-minute method.

Context: The importance of frozen-section diagnoses in the practice of pathology 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 been described that can be used in the frozen-section setting, we developed one 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 concentrated mucicarmine stain and a microwave oven, to reduce the total staining time to 3 minutes or less. Frozen tissue from normal colonic mucosa was used as a control, and skin from extramammary Paget disease for evaluation 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 connective tissue stained green.
Conclusion: This rapid and simple mucin staining technique can be used on frozen sections with no significant effect on the overall turnaround time, thereby aiding rapid diagnosis on frozen sections.