What happens when the wax appears crystalline during trimming?

When wax appears crystalline during trimming, it typically indicates that the wax is contaminated. Contaminated wax can result from the introduction of substances such as moisture, body fluids, or even residuals from previous specimens. These contaminants can disrupt the uniform structure of the wax, leading to a crystalline appearance when it cools and hardens.

In this context, it's important to ensure that the wax used for embedding is pure and free from impurities to maintain its consistency and quality. Crystalline structures are not desirable as they can affect the quality of the tissue sections, leading to problematic cutting and potential issues during microscopic examination. Therefore, recognizing and addressing contamination in the wax is crucial for achieving optimal histopathologic results.