Home Translating Report News Physicians Diseases Body Sites Lab tests Search
Home Diseases and Health Information


The surgical pathologist's diagnostic skills are challenged when a call from the surgeon or operating rooms requests an intraoperative consultation. The pathologist will take a small portion of tissue and proceed to rapidly freeze the tissue. Within a few minutes, the tissue can be cut by a specialized knife, known as a microtome. This microtome is housed in a machine known as a cryostat. It is a dedicated machine to perform the frozen sections, maintaining a constant freezing temperature for the tissue. This frozen tissue is then cut into very thin sections (thinner than the width of this line "I"), placed upon a microscope slide, and stained with specialized solutions. The slide is then reviewed under the microscope and a diagnosis is rendered. The entire process takes about 10 minutes but can change the course of the surgery. What was thought to be an infectious process by the surgeon, may now turn out to be a highly malignant tumor. Another common scenario is the evaluation of surgical margins, to ensure that the surgeon has completely removed a tumor.


Frozen Sections  
Intraoperative Cytology  
Commonly Used Terms  
Internet Links  



Interinstitutional comparison of frozen section turnaround time. A College of American Pathologists Q-Probes study of 32868 frozen sections in 700 hospitals.

Novis DA, Zarbo RJ.

Department of Pathology, Wentworth-Douglass Hospital, Dover, NH 03820, USA.


Arch Pathol Lab Med 1997 Jun;121(6):559-67 Abstract quote

OBJECTIVES: To study the intraoperative turnaround time for performing a frozen section (FS) and to examine pathology practice variables that influence it.

DESIGN: Over a 4-month period in 1995, participants in the College of American Pathologists Q-Probes laboratory quality improvement program prospectively collected data on up to 30 FS procedures performed on elective inpatient surgical cases and completed questionnaires profiling their FS practice characteristics.

SETTING: Surgical pathology laboratories serving private and public hospitals.

PARTICIPANTS: Seven hundred institutions located in North America (667), Australia (12), New Zealand (1), the United Kingdom (3), Hong Kong (1), Mexico (1), and Norway (1).

MAIN OUTCOME MEASURES: The 90% FS block completion time defined as the time interval, in minutes, within which the fastest 90% of all FS blocks were completed, measured from the time pathologists received FS specimens to the time they communicated FS results to the surgeon.

RESULTS: Participants submitted data on 32868 FS blocks. Ninety percent of FS procedures were completed within 20 minutes. Frozen section turnaround times exceeding 20 minutes, termed outlier turnaround times, were more likely to occur when more than one pathologist participated in the FS diagnosis, pathology residents and medical students participated in the FS procedure, the pathologist had to retrieve and review previous case material during the FS procedure, the pathologist simultaneously received additional specimens from other FS cases, the pathologist was unable to reach a final FS diagnosis, and when technical problems occurred during the FS procedure. Seventy percent of all participating hospitals completed 90% of their frozen sections within 20 minutes. The institutional 90% completion times were shorter for hospitals containing 300 or fewer occupied beds than for those containing more than 300 occupied beds.

CONCLUSIONS: The data suggest that 90% of FS block turnaround times can be performed within 20 minutes, measured from the time that pathologists receive FS specimens to the time that pathologists return FS diagnoses to surgeons.

Interinstitutional comparison of frozen section consultations. A college of American Pathologists Q-Probes study of 90,538 cases in 461 institutions.

Gephardt GN, Zarbo RJ.

Department of Pathology, Kennestone Hospital, Marietta, GA 30060, USA.

Arch Pathol Lab Med 1996 Sep;120(9):804-9 Abstract quote

OBJECTIVE: To assess concordant, discordant, and deferred diagnosis rates from frozen sections; to determine reasons for discordance; to identify pathologic processes associated with discordant diagnoses; to determine false-positive or false-negative rates for neoplasms; and to identify anatomic sites associated with discordant frozen section diagnoses.

DESIGN: Q-Probes study of the College of American Pathologists.

PARTICIPANTS: Four hundred sixty-one institutions participating in the Q-Probes program from November 1, 1990, through March 31, 1991.

MAIN OUTCOME MEASURES: Concordant and discordant diagnosis rates.

RESULTS: The frozen section concordance rate for diagnoses from the aggregate group was 98.58% and the discordance rate was 1.42%, when uncorrected for deferred diagnoses. During the study period, participating institutions accessioned 1,693,331 surgical pathology cases; 90,538 of these cases were evaluated by frozen section consultation, resulting in the examination of 121,668 specimens and 148,506 frozen section blocks. The majority of the frozen section discordances occurred because of misinterpretation of the original frozen section (31.8%), presence of diagnostic tissue in permanent sections of the frozen block when the frozen section was negative (30.0%), and presence of diagnostic tissue in the portion of the specimen not sampled by the frozen section (31.4%). Of the discordant diagnoses, 67.8% had false-negative diagnoses for neoplasm. The pathology processes and anatomic sites represented in discordant diagnoses are also evaluated.

CONCLUSIONS: High diagnostic accuracy of frozen section consultations was demonstrated. Frozen sections are used to evaluate a variety of pathologic processes and anatomic sites.

Indications and immediate patient outcomes of pathology intraoperative consultations. College of American Pathologists/Centers for Disease Control and Prevention Outcomes Working Group Study.

Zarbo RJ, Schmidt WA, Bachner P, Howanitz PJ, Meier FA, Schifman RB, Boone DJ, Herron RM Jr.

Department of Pathology, Henry Ford Hospital, Detroit, MI 48202, USA.

Arch Pathol Lab Med 1996 Jan;120(1):19-25 Abstract quote

OBJECTIVE--To evaluate the reasons (indications) for and immediate intraoperative surgical results (outcomes) associated with pathology intraoperative consultation.

DESIGN--In 1992 and 1993, surgeons collaborated with pathologists in 472 voluntarily participating institutions from the United States (462), Canada (7), Australia (2), and New Zealand (1) in a study jointly sponsored by the College of American Pathologists and the Centers for Disease Control and Prevention. Pathologists selected 20 consecutive intraoperative consultations and assembled a cover letter, a checklist questionnaire, and a copy of the corresponding surgical pathology report, all of which were sent to the surgeon(s) for retrospective evaluation.

PARTICIPANTS--The study was distributed to participants in the College of American Pathologists voluntary Q-Probes quality improvement and Surgical Pathology Performance Improvement programs and to Canadian and Australian hospitals with more than 200 beds.

RESULTS--Evaluation of 9164 cases established the five most common indications for intraoperative consultation: (1) establish or confirm diagnosis to determine type or extent of operation (51%), (2) confirm adequacy of margins (16%), (3) confirm nature of tissue to direct sampling for immediate culture or other laboratory study (10%), (4) expedite obtaining diagnosis to inform family or patient (8%), and (5) confirm sufficient tissue submitted to secure diagnosis in permanent section (8%). The information provided by the intraoperative consultation resulted in changed surgical procedures that were either modified, terminated, or newly initiated in 47%, 30%, 6%, 9%, and 28% of cases, corresponding respectively to each of the above five common indications. Rarely cited reasons for intraoperative consultation were to expedite obtaining diagnosis for surgeon's knowledge (3%), to facilitate patient management, other professional communication or discharge planning prior to permanent section availability (3%), academic protocol (< 1%), and consultation not needed or no reason for request (< 1%).

CONCLUSIONS--This multi-institutional, interdisciplinary database confirms that pathology intraoperative consultations, regardless of the initial indications, influence immediate patient care decisions, resulting in changed surgical procedures in an average of 39% of all operative cases.



Intraoperative and on-site cytopathology consultation: utilization, limitations, and value.

Gupta PK, Baloch ZW.

Department of Pathology, University of Pennsylvania School of Medicine, University of Pennsylvania Health System, Philadelphia, PA 19104, USA.

Semin Diagn Pathol 2002 Nov;19(4):227-36 Abstract quote

The intraoperative and on-site cytopathology can be successfully performed with a number of smear preparations. Specimen concentration technique is the preferred method. The Romanowsky stain such as Diff Quik used in our laboratory is economical, convenient, reproducible, and quick. This can be at times combined with Ultrafast pap or other rapid stains, which provide good nuclear details. Such evaluations are most valuable in the staging of epithelial tumors and primary diagnosis of a number of central nervous system lesions.

On-site and intraoperative diagnoses help triage the specimens for additional studies. This reduces the turn around time and makes the procedure cost-effective and beneficial to the patient.

An awareness of the "normal" adjacent structures and familiarity with the cytomorphology of the specimens in comparison to the exfoliative specimens is critical in developing a cytopathology service with high degree of sensitivity and specificity.

Value of cytology as an adjunctive intraoperative diagnostic method. An audit of 2,250 consecutive cases.

Scucchi LF, Di Stefano D, Cosentino L, Vecchione A.

Department of Experimental Medicine and Pathology, University La Sapienza, Rome, Italy.

Acta Cytol 1997 Sep-Oct;41(5):1489-96 Abstract quote

OBJECTIVE: To evaluate the role of intraoperative cytology (IC) in the improvement of diagnostic accuracy obtained by frozen section (FS) alone.

STUDY DESIGN: Comparison of 2,250 intraoperative cytologies performed along with frozen sections, with the final diagnoses achieved on paraffin sections.

RESULTS: In 18 cases the diagnoses were deferred until the paraffin sections at the time of intraoperative consultation. The diagnostic accuracy in distinguishing benign from malignant lesions by combined intraoperative cytology and frozen section was 99.2%. The accuracy rate is significantly higher than that reported in large series based on frozen section preparations alone. Sensitivity and specificity were, respectively, 98.2% and 100%. The diagnostic accuracy of each technique alone was 94.9% for FS (sensitivity 89.9%, specificity 97.9%) and 96% for IC (sensitivity 94.9%, and specificity 96.8%). Although specific diagnoses were more frequently formulated on the bases of frozen section examination, FSs were not diagnostic in 113 case in which cytology allowed a specific diagnosis.

CONCLUSION: Our results emphasize the increasingly important diagnostic role of intraoperative cytology as an adjunct to frozen section. The approach does have limitations.

Role of intraoperative cytopathology in pediatric surgical pathology.

Wakely PE, Frable WJ, Kornstein MJ.

Department of Pathology, Medical College of Virginia, Virginia Commonwealth University, Richmond 23298.

Hum Pathol 1993 Mar;24(3):311-5 Abstract quote

Studies regarding the efficacy of intraoperative cytopathology (IOC) of surgical specimens in the pediatric population are almost non-existent, despite their recent popularity in adults.

To determine the utility of IOC in children, we examined 58 cases from 54 pediatric patients (neonate to 18 years of age) who had cytologic smears performed in addition to or instead of frozen section (FS) examination during their surgical procedure. Knowing only the patient's age, sex, anatomic site, and any pertinent radiographic or historic data, three pathologists independently reviewed and issued a diagnosis using only the IOC smears. Subsequently, in 28 cases that also had accompanying FS examination, both IOC and FS analysis were interpreted for a composite final diagnosis. Three cases were judged unsatisfactory because of sparse cellularity of smears.

Correct classification of the smears as being benign or malignant for each pathologist was 98%, 94%, and 94% using IOC alone and 98%, 94%, and 96% using combined IOC and FS examination. The most frequent anatomic sites were bone (15 cases) and lymph node (14 cases). The most common diagnoses were malignant small round cell tumor (22 cases) and benign lymphoid tissue (10 cases). The records of all 55 cases were reviewed in the second phase of our study. Twenty-seven cases (49%) were found in which IOC diagnoses were rendered without a concurrent FS examination. These were correctly interpreted in 26 of 27 cases (96%) in the determination of a benign versus malignant disease process. The tissue sample measured < or = 2 cm in 15 of 27 cases (56%) in this latter group. Intraoperative cytopathology diagnoses in this group were rendered by various faculty members on call for FS examination and, in some cases, by fifth-year residents with faculty supervision. Without minimizing the degree of difficulty in the interpretation of pediatric IOC, we conclude that it serves as a useful supplement in FS diagnosis and, in some situations (particularly when tissue is limited), can replace histologic FS examination.

Henry JB. Clinical Diagnosis and Management by Laboratory Methods. Twentieth Edition. WB Saunders. 2001.
Rosai J. Ackerman's Surgical Pathology. Ninth Edition. Mosby 2004.
Sternberg S. Diagnostic Surgical Pathology. Fourth Edition. Lipincott Williams and Wilkins 2004.
Robbins Pathologic Basis of Disease. Seventh Edition. WB Saunders 2005.
DeMay RM. The Art and Science of Cytopathology. Volume 1 and 2. ASCP Press. 1996.
Weedon D. Weedon's Skin Pathology Second Edition. Churchill Livingstone. 2002
Fitzpatrick's Dermatology in General Medicine. 5th Edition. McGraw-Hill. 1999.
Weiss SW and Goldblum JR. Enzinger and Weiss's Soft Tissue Tumors. Fourth Edition. Mosby 2001.

Commonly Used Terms

Basic Principles of Disease
Learn the basic disease classifications of cancers, infections, and inflammation

Commonly Used Terms
This is a glossary of terms often found in a pathology report.

Diagnostic Process
Learn how a pathologist makes a diagnosis using a microscope

Surgical Pathology Report
Examine an actual biopsy report to understand what each section means

Special Stains
Understand the tools the pathologist utilizes to aid in the diagnosis

How Accurate is My Report?
Pathologists actively oversee every area of the laboratory to ensure your report is accurate

Got Path?
Recent teaching cases and lectures presented in conferences

Internet Links

Last Updated 1/5/2004

Send mail to The Doctor's Doctor with questions or comments about this web site.
Read the Medical Disclaimer.

Copyright © The Doctor's Doctor