One of the most common technical questions asked during Pathologists’ Assistant (PA) interviews is:
“How would you gross this specimen?”
For second-year PA students and new graduates, this question can feel stressful – especially if the specimen is something you have not covered yet during training or had a chance to gross firsthand. The good news is that interviewers do not expect you to know how to gross every single specimen. Instead, they want to see how you think, how you handle unfamiliar situations, and whether you understand safe and organized grossing practices.
This article walks through a clear and practical framework you can use to answer this question with confidence – even when the specimen is unfamiliar.
Why Interviewers Ask This Question
When an interviewer asks how you would gross a specimen, they are not expecting a perfect or institution-specific answer. What they are really looking for is whether you can:
- Work in a clear, step-by-step way
- Think about safety and specimen orientation
- Recognize the importance of margins and staging
- Use available resources and ask for help when needed
- Communicate your thought process clearly
Step 1: Be Honest and Upfront
If you have not grossed that specific specimen before, say so.
Being honest does not weaken your answer. In fact, it usually helps – as long as you explain how you would approach the case instead.
A simple start might sound like:
“I haven’t personally grossed this specimen type yet, but I can explain the general approach I use when I encounter a new or unfamiliar specimen that I would use here.”
This shows interviewers that you are self-aware, professional, and focused on patient safety.
Step 2: Use Key Resources Before Grossing
Before you begin grossing, experienced PAs rely on several resources. Interviewers expect you to mention these – especially if the specimen is unfamiliar.
1. Institutional SOPs
Your first step should always be reviewing your institution’s Standard Operating Procedures (SOPs). These outline:
- How the specimen should be oriented, opened or sectioned
- What measurements are required
- Which margins need to be submitted (and sometimes how many sections of the margin to submit)
- Lymph node expectations
- Any special handling or photo documentation requirements
2. Staging Protocols
Next, review staging guidelines (most commonly from the College of American Pathologists (CAP)). These help identify features important for staging such as:
- Tumor size (what size cutoffs will change the stage)
- Depth of invasion (what structure involvement(s) will change the stage?)
3. Colleagues and Supervisors
If anything in the SOP is unclear, ask for help? A senior PA, supervisor, or pathologist are all good resources to use. Knowing when to ask questions is an important part of being a safe and effective PA – not a weakness.
Step 3: Confirm Patient Information and Review Clinical History
Before grossing starts, confirm:
- Patient identifiers on the specimen container
- Information on the requisition (if you use paper reqs)
- Case details in the laboratory information system
Then review the patient history, including:
- Biopsy results confirming malignancy, if available
- Imaging findings (number, size, and location of lesions; involved structures)
- Whether the specimen is neoadjuvant, which can explain differences between imaging and gross findings
This background information helps you understand what you are seeing grossly and also highlights what exactly you should focus on to help the pathologist stage this case properly.
Step 4: Initial Gross Description
Start with a clear and organized description of the specimen:
- What specimen you’ve received
- Overall measurements in three dimensions
- Weight (if applicable)
- Descriptions of different specimen parts (if the specimen has multiple parts; for example, small bowel vs large bowel or prostate with seminal vesicles and vasa deferentia)
- Shape, colour, consistency, and texture
- Any abnormalities or irregularities
Focus mainly on the primary pathology, including:
- Tumor size
- Depth of invasion
- Involvement of nearby structures
Clear organization matters more than using complex language (if in doubt of how you should structure you gross description, refer to this article on formatting gross descriptions).
Step 5: Inking and Sectioning
If the specimen was not inked fresh, ink the margins or important surfaces before cutting – especially if orientation could be lost.
When describing your approach to sectioning the specimen, you will focus on:
- Assessing depth of invasion (if cancer)
- Measuring distances to all relevant margins
- Describe internal features such as hemorrhage, necrosis, or fibrosis
These details are important for diagnosis and staging of cancers, as well as important things to document for other pathologies.
Step 6: Secondary Findings and Lymph Nodes
After assessing the main pathology, look for:
- Additional findings
- Lymph nodes (if included with this specimen)
If you are unsure if there are a minimum number of lymph nodes to submit (for example if you were asked how to gross a gastrectomy specimen), tell the interviewer you would double check the SOP for this requirement.
Be sure to document:
- Your inking key
- Any ancillary studies (research tissue, flow cytometry, etc.)
- Photo mapping, if required
Uploading photos and maps allows the pathologist to easily review your findings.
Step 7: Block Selection and Dictation
When submitting tissue blocks:
- Sample all relevant margins
- Submit representative sections of the main tumor/pathology
- Include nearby normal tissue when appropriate
While requirements vary by institution, a commonly used general rule is one section per cm of the pathology unless the SOP states otherwise.
Again, defaulting to referring to the SOP here can help address the question of whether or not the tumor/pathology should be fully submitted or if only representative sections are required.
After submission, review and edit your gross description to make sure it is clear and complete.
Step 8: Processing and Cleanup
Finally:
- Load blocks onto the appropriate processor (a 12-hour processor is a common default)
- Clean your tools and workstation
- File any leftover tissue
- Set up your bench for the next case
Final Takeaway
This step-by-step approach – reviewing SOPs, checking staging guidelines, confirming clinical history, and grossing in an organized way – is how experienced Pathologists’ Assistants handle unfamiliar specimens in real practice.
In interviews, showing this thought process is far more important than listing the “perfect” sections or knowing exactly how many sections to take of a tumor in that specific specimen. A calm, structured answer demonstrates that you are safe, teachable, and ready for practice.
Related Resources
- Watch the full video: How to Answer “How Would You Gross This Specimen?”