Intraoperative Consultation

What is an intraoperative consultation?

A rapid pathology or specialist consultation performed during surgery to guide immediate patient management

What are the three principal reasons for intraoperative consultations?

Rapid diagnosis for surgical management

Proper tissue handling for special studies

Confirmation of lesional tissue

Why are intraoperative consultations considered urgent?

Surgical decisions must often be made immediately while the patient is still in the operating room

What surgical questions are commonly answered during intraoperative consultation?

Margin status

Malignancy

LN metastasis

Tissue adequacy

Infection

Specimen identification

Why is communication with the surgeon critical before processing tissue?

The pathologist/PA must clearly understand the clinical question being asked

What important clinical questions should be clarified before a frozen section?

Margin status

Diagnosis

Staging

Tissue adequacy

Special studies

Specimen handling

What is a frozen section?

Rapid microscopic evaluation of tissue frozen in a cryostat during surgery

What is the typical turnaround time foal for frozen sections?

Less than 20 minutes

What instrument is used to perform frozen sections?

A cryostat

What is OCT in frozen section processing?

Optimal Cutting Temperature compound used to embed tissue before freezing

Why is OCT important?

It stabilizes tissue during freezing and sectioning

What is a chuck in frozen section processing?

The mounting platform that holds tissue during cryostat sectioning

What is the purpose of the heat sink/weight during freezing?

To rapidly extract heat and freeze tissue evenly

What does “facing into the block” mean?

Trimming into tissue until the diagnostic surface is exposed

How many levels are commonly taken during frozen sectioning?

Two levels

What stain is typically used for frozen sections?

H&E

Why are frozen sections less accurate than permanent sections?

Limited sampling

Freezing artifact

Lack of special studies

Time constraints

What is the overall accuracy rate of frozen sections compared to permanent sections?

Approximately 94-97%

According to the College of American Pathologists, what is the acceptable major discrepancy rate for frozen sections?

3%

What are the 3 major categories of frozen section errors?

Sampling error

Interpretive error

Technical error

What is a sampling error in frozen section pathology?

The wrong tissue area is selected for evaluation

Who most commonly contributes to sampling errors?

The PA/grossing personnel

What is an interpretive error?

Incorrect microscopic diagnosis by the pathologist

What are some examples of technical problems during frozen sections?

Cryostat malfunction

Poor sectioning

Folding

Chatter

Staining issues

Why can incomplete clinical history lead to frozen section errors?

Important context needed for interpretation may be missing

What is a Category A discrepancy?

Minor disagreement with no impact on patient care

What is a Category B discrepancy?

Disagreement with some but not major impact on patient care

What is a Category C discrepancy?

Major disagreement with serious consequences for patient care

What is the function of hematoxylin in H&E staining?

Stains nuclei blue-purple

What is the function of eosin in H&E staining?

Counterstains cytoplasm and extracellular proteins pink

What is the purpose of the bluing agent?

Restores basic pH

Enhances hematoxylin staining

Why are alcohols used after eosin staining?

To dehydrate tissue

Remove excess water

Why is xylene used in frozen section staining?

Clears alcohol

Prepares slides for coverslipping

What is a gross examination-only consultation?

Intraoperative evaluation based on gross inspection without microscopy

What are common reasons for gross-only consultation?

Margin assessment

Specimen identification

Tissue adequacy

Why might a surgeon request gross-only evaluation instead of frozen section?

To save time or because gross findings alone answer the clinical question

What is a touch preparation?

Cytologic preparation made by touching tissue to a slide

What is a scrape preparation?

Cytology prep created by scraping tissue to obtain more cells

What is a squash preparation?

Smearing soft tissue between slides to create a thin cellular layer

What type of tissue commonly uses squash preparations?

Brain tissue

Why are touch preparations useful for tiny biopsy specimens?

They preserve tissue that could otherwise be lost during freezing

What stains are commonly used for touch preparations?

H&E or Diff-Quick

What specimens commonly undergo touch prep evaluation?

Sentinel LNs

Lymphomas

Needle cores

Tumor triage specimens

Why are scape preps preferred on less friable tissue?

More cells can be obtained without tissue destruction

What is telepathology?

Remote interpretation of pathology slides or live microscopic feeds

Why is telepathology especially useful in rural hospitals?

It allows remote pathologists to provide frozen section coverage

Does telepathology eliminate the need for on-site staff?

No — A PA, histotechnologist, or resident is still needed for specimen preparation

Besides diagnosis, what are additional uses of telepathology?

Consultation and teaching

What gynecologic specimens commonly require frozen section consultation?

Pelvic masses

Ovarian masses

Uterine masses

Sentinel LNs

What major question is often asked for ovarian masses intraoperatively?

Whether the lesion is benign, borderline, or malignant

What is commonly evaluated in head and neck SCC frozen sections?

Surgical margins

Why are parathyroid frozen sections commonly performed?

To confirm that tissue is truly parathyroid gland

What margins are commonly assessed in a Whipple procedure?

Pancreatic

Bile duct

Retroperitoneal margins

Why are distal margins evaluated in lower anterior resections?

To ensure complete tumor excision

What are common frozen section questions in pneumonectomy specimens?

Bronchial margins and LN staging

What is the major goal of intraoperative consultation for brain tumors?

Rapid diagnosis to guide surgical extent

Why are squash preparations especially useful in brain tumors?

CNS tissue is soft and spreads easily between slides

What margins are commonly assessed in cystectomy specimens?

Ureteral margins

Why are intraoperative consultations performed for prosthetic joints?

To evaluate for infection

What is the biggest limitation of frozen section diagnosis?

Limited sampling

What artifact is characteristic of frozen sections?

Ice crystal artifact

Why are some special studies difficult during frozen section evaluation?

There is insufficient time and tissue preparation

Why are permanent sections considered the gold standard?

Better fixation

Processing

Morphology

Ancillary testing

Why is adequate tissue triage important during intraoperative consultation?

Tissue may need to be reserved for:

• Flow cytometry

• Cultures

• Molecular testing

• Cytogenetics

What is meant by “margin status”?

Whether tumor extends to the surgical edge

Why is intraoperative margin assessment clinically important?

Positive margins may require additional surgical resection immediately

What is a sentinel lymph node?

The first draining lymph node from a tumor site

Why are sentinel LNs evaluated intraoperatively?

To rapidly determine metastatic spread and guide surgery

Why are frozen sections generally avoided on tiny needle cores?

Tissue loss can compromise permanent diagnosis

Why is intraoperative pathology considered a high-pressure environment?

Rapid decisions directly affect surgical management and patient outcomes