Rapid Preparation of High-Quality Frozen Sections Using a Membrane and Vacuum System Embedding Machine

BACKGROUND A wide variety of embedding techniques have been employed to process frozen sections for Mohs micrographic surgery. Prospective data comparing different techniques are lacking. OBJECTIVE The purpose of this study was to compare tissue processing times and slide quality using the three embedding techniques. METHODS Seventy-five consecutive Mohs surgery tissue specimens, measuring 1 cm in diameter, were prospectively randomized to processing with the CryoHist, the Cryocup, or the Miami Special. Tissue preparation times were recorded, and slide quality was evaluated. Tissue specimen preparation was standardized to exclude the use of relaxing incisions or other tissue manipulations. In a separate evaluation, slide quality was retrospectively evaluated for 50 large specimens (>2.5 cm) processed with the CryoHist machine. RESULTS The mean tissue processing time was 11.4 minutes using the CryoHist, 12.9 minutes using the Cryocup, and 12.6 minutes using the Miami Special. Slide quality, using epidermal edge as a primary end point, was superior with the CryoHist compared to the other methods. For large (>2.5 cm) en bloc Mohs specimens processed using the CryoHist, the slide quality was excellent with 92.3% of epidermal edge obtained. CONCLUSIONS The fully automated CryoHist embedding machine enables high-quality frozen sections to be processed in less time than the Cryocup or the Miami Special. Slide quality is excellent, even for larger specimens.