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A Primer on Intraoperative Consultations


"Someone go wake the pathologist, we need a frozen section!" When the doctor utters those words (or something similar) in the midst of surgery, it means he needs to send a tissue specimen to the pathology lab for an immediate intraoperative consultation (IOC).

Just like getting another surgeon's opinion during a procedure, an IOC from a pathologist helps guide the surgeon's hand while the patient is still under anesthesia. In most cases, the IOC will have been scheduled ahead of time, but sometimes the surgeon won't discover the need until surgery is already in progress. Here's a guide to handling IOCs.

What are intraoperative consultations?
The three basic types of pathology IOCs are: gross examination, frozen section and cytopathology. The intent and indication behind each request determines which types are best suited for the case (see "Accepted Indications for Intraoperative Consultation" on page 81).

Gross examination consultation. Gross examination of the specimen occurs with all IOCs, either as the starting point for frozen section or cytology consultations or as the end point for a gross examination diagnosis. It involves the pathologist evaluating the tissue for features of disease with the naked eye or a magnifying lens. The surgeon and pathologist then review the tissue findings during the procedure, either in the OR or the surgical pathology suite. Gross examinations generally require between five and 10 minutes.

Best uses: To give an accurate assessment of many surgical margins (such as colorectal or breast cancers well away from surgical margins) and help determine the necessity of further operative procedures without the use of a frozen section.

Frozen section consultation. A frozen section involves gross examination of the specimen and selection of a representative portion of the tissue (such as visually abnormal tissue) to be frozen, sectioned and stained for preparation of microscopic slides. The pathologist then examines the slides and renders a tissue diagnosis.

Frozen sections generally take about 20 minutes from receipt of the tissue by pathology to communication of the diagnosis to the surgeon. They're labor- intensive, require expensive equipment and personnel coordination and have higher rates of acceptable error (3 percent to 5 percent) compared to routine examination (1 percent or less).

Best uses: To establish a rapid histopathologic diagnosis of a pathologic process, including, when indicated, representative assessment of surgical margins. Frozen sections can also establish or confirm the tissue diagnosis; evaluate surgical margins; provide an initial diagnostic category to determine the need for ancillary testing (culture, flow cytometry, cytogenetics) on fresh tissue; and determine specimen adequacy for final evaluation.

Cytopathology consultation. When done in support of a frozen section diagnosis, cytology consultation includes gross examination of the specimen; scraping, crushing or performing touch preparations of the tissue; and staining the tissue for preparation of microscopic slides. When only fluid is collected, a representative portion of the fluid is prepared and stained. The pathologist then examines the slides and renders a cytologic diagnosis.

Cytology consultations take about five to 20 minutes, start to finish. They're limited to cellular features of the tissue and don't generally allow examination of what the cells look like in the context of the rest of the tissue. In the hands of a good cytopathologist, though, they can be informative.

Best uses: To support a tissue diagnosis at frozen section; provide an initial diagnostic category to determine the need for ancillary testing; and determine specimen adequacy for final evaluation.

Handling specimens and communicating diagnoses
For IOCs, follow the same general pathology specimen handling guidelines your facility sets for any type of consultation:

  • specify at least two patient identification data points;
  • include the pathology requisition;
  • identify the type of intraoperative consultation requested;
  • indicate to whom the consultation findings are to be reported and at what location; and
  • follow all other tissue submission guidelines.

Before communicating the IOC findings, the pathologist or staff member conveying the diagnosis must confirm the identity of the patient. Document the IOC and findings in the final surgical pathology report.

Scheduling your IOCs
IOCs involve the coordinated effort of multiple departments and can be delayed if not scheduled properly. Many pathologists, citing constraints on resources both in pathology and surgery departments as well as an increased likelihood of diagnostic error without sufficient tissue sampling, frown on "curiosity" IOCs and limit them to only those cases that fall within the four main indications seen in the table below. Jeffrey L. Myers, MD, chair of anatomic pathology at the University of Michigan, has a different philosophy: "My current approach is, 1) surgeons are pretty smart and generally good doctors; 2) patients deserve quick answers as long as we can do it without jeopardizing their care; and therefore, 3) if someone asks for a frozen, I just do it."

Whether your pathologists are conservative about IOCs or more like Dr. Myers, effective scheduling of intraoperative consultations helps eliminate bottlenecks at the path lab that can delay cases and increase anesthesia time.

Accepted Indications for Intraoperative Consultation

Indication for Intraoperative Consultation

Type of IOC to Request

Establish or confirm tissue diagnosis to determine the type or extent of procedure.

  • Frozen section
  • Cytopathology examination

Confirm adequacy of surgical margins.

  • Gross examination
  • Frozen section

Confirm nature of tissue to direct further sampling and/or laboratory studies to be performed on fresh tissue (for example, culture, flow cytometry, cytogenetic evaluation, gene rearrangement).

  • Frozen section
  • Cytopathology examination (Reserve tissue in specialized media or conditions as needed for ancillary studies.)

Confirm sufficient tissue submitted to secure diagnosis at permanent section.

  • Frozen section