What is the outcome if tissue blocks are thicker than recommended?

When tissue blocks are thicker than recommended, the most significant outcome is that they will be processed incorrectly. Thicker tissue sections can lead to inadequate penetration of fixatives, dehydrating agents, and clearing agents during the processing steps. This uneven processing can result in poor preservation of cellular morphology and antigenicity, ultimately affecting the quality of the histological slides.

In tissue processing, uniform thickness is crucial for ensuring that the fixative effectively permeates the entire specimen and that subsequent staining techniques yield accurate results. If the tissue is too thick, certain areas may be under-fixed or inadequately dehydrated, leading to artifacts, distortion, or incomplete staining, which compromises diagnostic accuracy. This is why adhering to recommended thickness guidelines is essential in histopathology to ensure reliable outcomes.