Preanalytical variables in surgical pathology: practical sources of diagnostic error before microscopic...

To review clinically important preanalytical variables in surgical pathology and their effects on diagnostic accuracy, ancillary testing, and patient safety.

A narrative review was developed from selected literature on surgical pathology preanalytics, fixation, specimen handling, histotechnology, immunohistochemistry, molecular testing, tissue contamination, and quality improvement. Emphasis was placed on practical variables that affect routine anatomic pathology workflows.

The diagnostic value of a surgical pathology specimen is shaped before microscopic interpretation. Ischemia time, delayed or inadequate fixation, tissue thickness, container and transport problems, labeling discrepancies, poor orientation, grossing variability, histotechnical artifacts, and tissue contamination can compromise morphology, margin assessment, staging, biomarker interpretation, and molecular testing. These effects are especially consequential in small biopsy specimens and precision oncology specimens, in which the same limited tissue may be required for diagnosis, immunohistochemistry, fluorescence in situ hybridization, polymerase chain reaction-based testing, and next-generation sequencing. Gross examination is a particularly important pathology-controlled preanalytical step because block selection determines what can be assessed microscopically.

Preanalytical control should be regarded as a diagnostic quality and patient safety process rather than a technical background activity. Standardized fixation, specimen tracking, communication, grossing protocols, histotechnical quality assurance, and tissue stewardship are essential to reliable surgical pathology practice.