After a surgical biopsy, the tissue sample (specimen) is sent to the Pathology Department for processing and further examination. The preliminary results are usually available within 1 to 3 working days from the time of the biopsy. The results can take 1 to 3 weeks.  

Once the Pathology Department receives the specimen, we:

• Preserve it in formalin. For large specimens, this can take up to 24 hours. 
• Slice it into smaller sections. If it’s a very small specimen, the entire sample will be examined. 

The pathologist examines, measures, and describes each section, noting any features that may help with diagnosis.

Once the visual examination is complete, we prepare the specimen so it can be examined under a microscope. Tissue samples are very delicate, so they need to be preserved to prevent damage during examination. To do this, we: 

• Place each tissue sample into a small plastic cassette. These cassettes are labeled with a unique number that is traceable to your name and medical record number.
• Place the cassettes in additional fixatives in a tissue processor. Overnight, the processor removes water from the tissue and replaces it with wax. 
• Embed the tissue sample in a wax block. 
• Slice the tissue-containing wax mold into very thin slices and placed them on glass slides.
• Apply a series of stains to the tissue samples. Stains highlight specific features of the tissue. 
• Cover each slide with a thin piece of plastic called a coverslip. 

The slides are examined by a pathologist. The pathologist:

• Measures and describes each slide.
• Notes details that may help your physician to create a treatment plan. For example, the pathology report for a cancer tissue sample will include details about the size of the tumor and extent of normal tissue around it (margin). 

After this analysis is complete, we send the report to your doctor. 

Additional testing

In most cases, the pathologist can make a timely and precise diagnosis. In some instances, the findings aren’t as straightforward. In these cases, we may:

• Perform further testing, including the use of additional stains. For example, immunohistochemistry tests use specific stains to look for certain tumor markers.  
• Order genomic sequencing. This provides a more specific classification of a tumor based on the genetic mutations it contains. 
• Request review by other pathologists.
• Send slides to specialized pathologists outside of Kaiser Permanente, if needed.