In histopathology sample handling, tissue samples should be no larger than what diameter?

In histopathology sample handling, tissue samples should be no larger than what diameter?

• A. 0.5 cm
• B. 2 cm
• C. 5 mm
• D. 1 cm

Answer: (D)

The main idea is that fixation and subsequent processing rely on the fixative penetrating the tissue quickly and evenly. Tissue that is too large can have a poorly fixed center, leading to autolysis, artifacts, and unreliable staining. Therefore, the common guideline is that the greatest dimension should be no more than about 1 centimeter. If a specimen is larger, it should be cut into smaller fragments, each about 1 cm or smaller, to ensure thorough and uniform fixation. While smaller sizes (like 5 mm) also fix well, 1 cm is the standard maximum that balances fixative penetration with practical handling. Larger sizes would risk under-fixation, making 1 centimeter the best choice.

The main idea is that fixation and subsequent processing rely on the fixative penetrating the tissue quickly and evenly. Tissue that is too large can have a poorly fixed center, leading to autolysis, artifacts, and unreliable staining. Therefore, the common guideline is that the greatest dimension should be no more than about 1 centimeter. If a specimen is larger, it should be cut into smaller fragments, each about 1 cm or smaller, to ensure thorough and uniform fixation. While smaller sizes (like 5 mm) also fix well, 1 cm is the standard maximum that balances fixative penetration with practical handling. Larger sizes would risk under-fixation, making 1 centimeter the best choice.