4
Diagnostic Quality Assurance in Cytopathology
abnormal
features.
The
modern
cytopathology laboratory
should use a computerized file system. Such a system permits
laboratory professionals to have information on all previous
cytologic or histologic reports on a given patient available when
the new cell sample is being evaluated. Modern computerized
data collection and retrieval systems are also essential for con-
tinuing quality control and assurance mechanisms. A record of
workload and diagnostic performance should be maintained as
a part of the personnel data file for each cytotechnologist.
Internal Quality Assurance Mechanisms
CLIA 88 Update
The standard requirements of CLIA 88 affecting the cytopathol-
ogy laboratory in the United States have been published in the
federal register.57 Recent updates of CLIA 88 have added more
rules and regulations to the already highly regulated field of
gynecologic cytology.58 In addition to the following:
1. Prospective 10% review of negative gynecologic cell
samples including high-risk cases may be performed,
prior to reporting patient results, by the pathologist,
supervisor, or cytotechnologist who has had 3 years of
continuous cytology experience within the past
10-year period.
2. Retrospective re-evaluation for current high-grade
squamous intraepithelial lesions (HSIL) or cancer
cases with a review of negative specimens obtained
within the previous 5 years should be performed
when clinically significant discrepancies are found
that will affect current patient care; notification of
physician and an amended report are required.
3. Cytology/histology correlation for gynecologic
cases with a diagnosis of HSIL, adenocarcinoma, or
other malignant neoplasm should be carried out
with causes of discrepancies, such as sampling or
diagnostic errors on biopsy or cytologic cell samples,
documented.
new rules require:
1. An evaluation of the case reviews of each individual
against the laboratory's overall statistical values,
documentation of discrepancies including reasons for
deviation, and, if appropriate, corrective action taken.
2. A workload limit based on individual's performance,
every 6 months, based on review of 10% negative
cases and comparison of individual's interpreta-
tion with the pathologist should be established. The
maximum workload limit is 100 slides in 24 hours.
Pathologists who perform primary screening are
not required to include tissue pathology slides and
previously examined cytology slides in the 100-slide
workload limit.
3. The pathologist should confirm all nongynecologic
cases and interpret each gynecologic slide as reactive
or with any abnormality, including atypical squa-
mous cells of undetermined significance (ASCUS),
atypical glandular cells (AGC), low-grade squamous
intraepithelial lesion (LSIL), high-grade squamous
intraepithelial lesion, and carcinoma. The report
needs to be signed by the pathologist to reflect
review or if a computer report is generated it must
reflect an electronic signature authorized by the
pathologist.
4. Reports with narrative descriptive nomenclature for
all results are recommended. Corrected reports must
include the basis for correction.
5. Records of initial examinations and all rescreening
results must be documented.
6. Annual statistics should include total gynecologic
and nongynecologic cases, by specimen type, and
diagnosis including unsatisfactory, cytology/histology
correlation discrepancies, and cases reclassified from
normal to LSIL or higher.
7. When performing evaluations using automated and
semiautomated screening devices, the laboratory must
follow manufacturers' instructions for preanalytic,
analytic, and postanalytic phases of testing, as appli-
cable, and meet the applicable requirements.
8. Enrollment for proficiency testing (PT) as required by
Centers for Medicare and Medicaid Services. For more
details see section on External Quality Assurance
Mechanisms.
Rapid Re-evaluation
Rapid rescreening (RR) of cervical smears for internal quality
control has been advocated by a number of authors.59-62 In a
meta-analysis of 14 studies by Arbyn and Schenck,61 RR was a
more effective quality control method than full rescreening of
a 10% random sample. Although RR has received great support
as the quality control method of choice in some countries, the
cost-effectiveness of its potential advantage is still unknown.
Computer-Assisted Quality Assurance
Mechanisms
With the approval by the Food and Drug Administration (FDA)
of two automated instruments for quality assurance rescreen-
ing of gynecologic cytology, namely, the Focal Point System by
Becton Dickinson/TriPath and the ThinPrep Imaging System
(TIS) by Cytyc Corporation, automated screening of gynecologic
cytologic samples for quality assurance has become a practical
reality.
Detailed proposed specifications for automated instruments
have been published,63 and reviews of the instruments and the
concepts can be found in Chapter 34, Automation of Pap Smears,
and in the
Compendium on the Computerized Cytology and Histol-
ogy Laboratory64
and in the
Compendium on Quality Assurance, Pro-
ficiency Testing and Workload Limitations in Clinical Cytology.65
The development of automated cytologic devices had to
pass two milestones: the application of the system as a qual-
ity assurance or quality control instrument, and the application
of automated devices for primary screening of gynecologic cell
samples.66,67
The AutoPap System, now named Focal Point System, showed
superior sensitivity and specificity for detection of abnormal
slides with ASCUS and more severe lesions when compared to
current practice.68 Other investigators had similar results.69-71 The
Focal Point System is a more effective way of detecting errors
within a laboratory and reduces the false-negative rate (FNR) by
greater than 25% according to Renshaw et al.72
61
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