Cytology - COLA

Cytology FactSheet 6Cytology Quality ControlCorrelation of Cytology ReportsThe microscopic examination of cytology specimens issubjective and can be affected by many factors thatmake 100% accuracy difficult to achieve. Some of thesefactors are:• Inadequate or improper samples• Improper fixation or staining• Overlapping cells or obscuring inflammation• Difficulty in identifying abnormal cellsIt is important for your laboratory to continuously monitorand compare the performance of the individualsscreening and interpreting slides. Required cytologyquality control activities represent the best ways foryour laboratory to monitor and improve the accuracy ofcytology examination procedures.One of these quality control processes is the correlationof cytology and histopathology reports. Your cytologyquality control procedures must include a comparison ofclinical information, when available in the laboratory,with cytology reports, and a comparison of all gynecologiccytology reports with a diagnosis of high-gradesquamous intraepithelial lesion (HSIL), adenocarcinoma,or other malignant neoplasms with histopathologyreports, if they are available in the laboratory (or in storage).You must determine the causes of any discrepanciesbetween the cytology and histopathology diagnosesin these cases.Comparisons of Clinical InformationRequisitions for gynecologic cytology (Pap smears) arerequired to contain key pieces of information that canhelp to interpret and confirm the accuracy of cytologyreports. At minimum this information should include:• Sex of the patient• Date of last menstrual period• Patient age or date of birth• Prior abnormal cytology or biopsy• Pregnancy or menopauseIn the comparison of the diagnosis to patient clinicalinformation, laboratories will typically perform thisreview prior to releasing results. This can be a simplecomparison of the patient’s information to the final diagnosis.For example: An atrophic smear (usually characteristic ofa post-menopausal woman) from a 21-year-old femalewith a last menstrual period of 2 weeks ago constitutesinconsistent findings and must be resolved.This may require going back and pulling the slide(s) forthe case and performing a review. If a discrepancy isnoted, then this should be documented, and the personoriginally reviewing the case must review any discrepancies.Comparison of Cytology and HistopathologySpecimens/ReportsThe Pap smear is a screening test to detect potentialgynecologic cancers. An abnormal Pap smear leads tothe patient having additional procedures performed thatwill result in histopathology specimen(s) beingobtained. There are also times when a patient may havea biopsy performed based on criteria other than anabnormal Pap smear. The purpose of correlating thediagnosis from the Pap smear with the histopathologydiagnosis is to ensure accurate diagnosis and appropriatetreatment of the patient.Since the specimens are obtained at different times andfrom different specimen sampling sites, there is a distinctprobability that there will be some discrepancy inthe results. Discrepancies can result from samplingerrors on Pap smear or biopsy, and from diagnosticerrors on the Pap smear or biopsy.If the laboratory performing the Pap smear also readsthe biopsy or has access to the biopsy (perhaps througha related laboratory), there is an obligation to correlatethe findings. If a discrepancy is identified, you mustdetermine the cause of the discrepancy between thecytology and histopathology diagnoses.There are multiple ways to implement this process. Themethod adopted by laboratory management will be6-1© COLA--1/09. COLA Cytology FactSheet® is a registered trademark of COLA.

Cytology FactSheet 6dependent upon how the laboratory is organized, howresponsibilities are defined, and what procedures areperformed onsite. Either the cytology or histopathologydepartment can initiate these reviews.Even though cytology/histopathology correlation is onlyrequired for HSIL and above gynecologic cytology specimens,or Pap smears, your laboratory may want to correlatecervical biopsies containing HSIL or malignancy tonegative or atypical Pap smears; or correlate Pap smearswith a diagnosis of low grade squamous intraepitheliallesion (LSIL) to corresponding biopsies in addition toHSIL Pap smears. This comparison can be a great way toimprove performance in your laboratory by learning fromtissue-confirmed cases of dysplasia.Personnel for the Slide ReviewThere are no specific requirements that specify whichcytology personnel must perform the cytology/histopathologycorrelation activities. Cytotechnologistsor cytology supervisors may initially review thePap smear slides that are correlated with the correspondingbiopsy slides. However, all diagnostic discrepanciesand histopathology slides, if reviewed, must be confirmedby a pathologist. When diagnostic discrepanciesare found, the individuals who originally diagnosed thecase must review the pertinent slide discrepancies.Written ProceduresPrior to developing formal written procedures for cytology/histopathologycorrelation, determine the bestmethod for performing this quality control activity inyour laboratory. Some scenarios to consider mayinclude:• Your pathologists reviews corresponding Papsmears at the time the cervical/endocervical biopsyslides are read• A quality control technologist compiles a summaryof HSIL and above Pap smears at defined timeframes(daily, weekly, monthly, or quarterly) andsearches for corresponding biopsy reports• Files are searched for previous Pap smear slideseach day that biopsy results are received• Another method that works best in your laboratoryfor comparing the HSIL and above Pap smearslides/reports and corresponding biopsy specimens/reportsin a timely manner• In addition to HSIL and above Pap smears, yourlaboratory may want to correlate negative, atypical,or LSIL Pap smear slides as wellFormalize your laboratory practices into written proceduresfor comparing the diagnoses from gynecologiccytology reports to other information available to thelaboratory, including clinical patient information, andhistopathology reports. Your written procedure shouldinclude:• The time frame for performing the cytology/histopathologycorrelation and slide review(i.e. when biopsy slides are reviewed? At a laterdate? Monthly? Quarterly?)• Your laboratory’s method for case selection forcytology/histopathology correlation (i.e. HSIL andabove Pap smear reports; also include negative,atypical, LSIL?)• The criteria used to determine a discrepancybetween gynecologic cytology reports and the correspondinghistopathology report• The method used by your laboratory to determinewhich cytology and histology slides to review (i.e.2-step difference in diagnostic categories betweenPap smear and biopsy? Other method?)• Description of what constitutes a diagnostic discrepancyfound in the slide review• The actions that will be taken to resolve any discrepanciesidentified by the comparison, includingwhen corrected reports would be sent to thephysicianTimeframeThere is no required timeframe for these cytology/histopathologycorrelations to be completed.Correlations between the gynecologic cytology reportsand histopathology reports may take place at the timethe biopsy is read, or at later date. COLA recommendscompleting the slide reviews as quickly as possible tominimize any adverse effects potential slide discrepanciesmight have on patient treatment and follow-up.Many laboratories find it beneficial to perform theseslide reviews at the time the tissue specimens are read,and then summarize the results monthly so that trendsin diagnostic discrepancies or other problem areas canbe identified and remedied in a timely manner.For example, in one laboratory the pathologists mayreview corresponding Pap smear slides at the time a cervicalbiopsy is read and make comments about the6-2© COLA--1/09. COLA Cytology FactSheet® is a registered trademark of COLA.

Cytology FactSheet 6review on the specimen requisition, documentation log,or other paperwork. If a corrected or amended report isneeded, it can be addressed by the pathologist at thistime. A quality control cytotechnologist compiles andrecords the pathologist slide review comments on a formaldocument monthly so they can be summarized forannual statistics.In another example, a laboratory determines that itworks best in their setting for a quality control cytotechnologistto compile a list of HSIL and above Pap smearson a monthly basis, and then run a computer check forany corresponding biopsies. Cytology slides are selectedfor review based on the laboratory’s selection criteria,and slide review results recorded. The pathologist examinesthe results of the cytology/histopathology correlationactivities compiled by the cytotechnologist, andreviews pertinent slides. Confirmed discrepant cases aresummarized and included in the annual statistics.Corrected reports are issued, if needed, and personnelreview slide discrepancies.Determining Diagnostic DiscrepanciesWhat is considered a diagnostic discrepancy in your laboratory?How do you determine which slides to bereviewed? Many laboratories use a two-step differencein diagnosis as an indicator for the Pap smear slide andpossibly the biopsy slide to be reviewed.Two-step Comparison TablePAP CATEGORYNegative, no intraepithelial lesion(NIL), within normal limits (WNL)ASCUS, atypical cellsMild dysplasia, HSIL, CIN 3Moderate dysplasia, HSIL, CIN 3Severe dysplasia, HSIL, CIN 3,malignantCauses of Discrepant DiagnosesMany laboratories find it helpful to breakdown the causesof discrepant diagnoses between the Pap smear andTISSUE CATEGORYMild dysplasia, LSIL, or CIN 1 and aboveModerate dysplasia, HSIL, CIN 2 or CIN3, malignantNegative, severe dysplasia, CIN 3 andaboveNegative, atypical, malignantNegative, atypical, mild dysplasia, LSIL,CIN 1biopsy specimens for calculating laboratory statisticsand for determining continuing education needs. Causesfor diagnostic discrepancies may include:• Sampling error on biopsy• Sampling error on Pap smear• Diagnostic error on biopsy• Diagnostic error on Pap smearExample of sampling error on biopsy: A laboratory diagnosesa liquid-based Pap as HSIL, moderate dysplasia,CIN 2. A cervical biopsy is performed two months laterwith a negative diagnosis. The Pap smear is reviewedand the diagnosis of HSIL is reconfirmed. The cervicalbiopsy failed to contain the transition zone so the laboratorycoded this case as a sampling error on the biopsy.Example of sampling error on liquid-based Pap smear: Alaboratory diagnoses a liquid-based Pap as atypicalsquamous cells of undetermined significance (ASCUS).A cervical biopsy is performed two months later with adiagnosis of HSIL, severe dysplasia, CIN 3, with abnormalcells high in the endocervical canal. The Pap smearis reviewed and the diagnosis of ASCUS is reconfirmed,however, it is noted that there are no endocervical cellspresent on the slide. The laboratory coded this case as asampling error on the Pap smear.Example of diagnostic error on biopsy: A laboratorydiagnoses a liquid-based Pap as HSIL, severe dysplasia,CIN 3. A cervical biopsy is performed two months laterwith a diagnosis of squamous atypia. On review, thebiopsy was found to contain CIN 2(undercall). The laboratory codedthis case as a diagnostic error on thebiopsy.Example of diagnostic error on Papsmear: A laboratory diagnoses aconventional Pap as HSIL, severedysplasia, CIN 3. A cervical biopsy isperformed two months later anddetermined to be negative. Afterreview, it was determined thatendometrial cells had been mis-interpretedas HSIL (overcall). The laboratorycoded this case as a diagnosticerror on the Pap smear. In addition, acorrected report was issued and thephysician notified so that the patient would not have furthertesting performed to find the source of the HSIL.6-3© COLA--1/09. COLA Cytology FactSheet® is a registered trademark of COLA.

Cytology FactSheet 6DocumentationAll cytology quality control activities should be documentedin a manner that allows them to be summarizedover time to determine trends for personnel improvementand development of continuing educational needsof your staff.Documentation of comparisons should include:• Case accession numbers, dates, diagnosis, andpersonnel who reported the gynecologic cytologycase• Case accession numbers, dates, diagnosis, sourceof specimen, and personnel who reported thebiopsy case• Results of any slide reviews, including documentationof diagnostic discrepancies• Categorization of slide reviews, such as the numberof sampling or diagnostic errors in cytology orbiopsy specimens• Corrective action taken in response to the discrepancy,and notification of the attending physician orissuance of an amended or corrected report, ifneededThe results of these correlations are summarized foryour laboratory’s annual statistics, which include:• The number of gynecologic cases diagnosed ashigh-grade squamous intraepithelial lesion (HSIL),adenocarcinoma, or other malignant neoplasmwhich have histopathology available for comparison• The number of cases with discrepant cytology andhistology results, and• The number of re-screened negative or normalgynecologic cases reclassified as low-grade squamousintraepithelial lesion (LSIL), HSIL, adenocarcinoma,or other malignant neoplasm (if your laboratoryreviews negative gynecologic cytology caseswith corresponding dysplastic or malignant tissuebiopsy slides)These correlations may also be used to:• Evaluate individual performance• Compare an individual’s statistics to the overall labstatistics to determine diagnostic discrepancytrends over time• Establish, reassess, and adjust maximum workloadlimits• Identify individual continuing education needsA sample form (with instructions) for documentation ofcytology/histopathology correlation is included.Cytology Quality Control, including cytology/histopathology correlations (760-763), is addressed inCOLA criteria 755-775.6-4© COLA--1/09. COLA Cytology FactSheet® is a registered trademark of COLA.

Cytology FactSheet 6Instructions for Completing the GynecologicCytology/Histopathology Correlation LogCOLUMNPATIENT NAME & CYTOLOGY ACCESSIONNUMBERCYTOLOGY RESULT, INITIALS & DATESURGICAL ACCESS #TISSUE RESULT, SITE, INITIALS & DATESLIDE REVIEWS, INITIALS & DATECORRELATION CODE & COMMENTSINSTRUCTIONSRecord the patient name and laboratory accession number of the Papsmear caseRecord the results/diagnosis of the Pap smear case, the initials of thecytotechnologist and pathologist who examined the case and the datethe case was reportedRecord the laboratory accession number of the surgical biopsy specimenthat corresponds to the Pap smearRecord the results/diagnosis of the surgical biopsy specimen, the sitesampled, such as cervix, endocervix, endocervical curettage, etc., the initialsof the pathologist who diagnosed the case and the report dateRecord the results of the cytology or biopsy slides reviewed due to noncorrelation,the initials of the cytotechnologist or pathologist reviewingthe case, and the date of the reviewRecord the correlation code (see below) based on the slide review andany pertinent comments such as scant specimen, poor preservation, fewabnormal cells present, etc.Correlation CodesCNSDBCCORRELATION (i.e. the diagnosis of the Pap smear and corresponding surgicalspecimen agree within 2-steps)NONCORRELATION (i.e. The diagnosis of the Pap smear and correspondingsurgical specimen DO NOT agree within 2-steps). The slides from thesecases are reviewed to determine the reason for the non-correlation.SAMPLING ERROR – the reason for the non-correlation is determined to bedue poor sampling (i.e. the abnormal cells were not present in the specimenreviewed)DIAGNOSTIC ERROR – the reason for the non-correlation is determined tobe due to a diagnostic error. For example, the abnormal cells were not originallyidentified in the specimen, but now in retrospect they ARE identifiedin the specimen (Undercall); or in retrospect, the abnormal cells that wereoriginally reported are determined not to be abnormal after the slidereview. They could have been overcalled due to staining artifact, a normalprocess that mimics an abnormal process, lack of experience with this typeof case, etc.BIOPSY SPECIMEN such as cervical, endocervical, vaginal, endocervicalcurettage, cervical cone, hysterectomy specimen, etc.CYTOLOGY SPECIMEN such as conventional Pap smear, ThinPrep Pap,SurePath Pap, or other liquid-based monolayer preparation6-5© COLA--1/09. COLA Cytology FactSheet® is a registered trademark of COLA.

Cytology FactSheet 6GYNECOLOGIC CYTOLOGY/HISTOPATHOLOGY CORRELATION LOG: MONTH, YEAR: __________PATIENT NAME &CYTOLOGY ACCESSIONNUMBERCYTOLOGY RESULT,INITIALS & DATESURGICAL ACCESS # TISSUE RESULT, SITE,INITIALS & DATESLIDE REVIEWS,INITIALS & DATECORRELATION CODE &COMMENTSC = Correlation N = Non-correlation S = Sampling error D = Diagnostic error B = Biopsy Cy = CytologyReviewed by: ____________________________6-6© COLA--1/09. COLA Cytology FactSheet® is a registered trademark of COLA.